Name: Easy Cast Iron Flank Steak with Chimichurri Butter Recipe
Prep time: 10 min
Cook time: 10 min
Total time: 20 min
Cuisine: American
Ingredients: 1.5-2 pounds flank steak, about 1-1.5 inches thick; 2 heaping teaspoons Morton kosher salt; 1 teaspoon pepper; 1 teaspoon granulated garlic; Grape seed oil (enough to generously coat bottom of pan); 2 Tablespoons salted butter, room temperature; 1 Tablespoon chopped fresh parsley; 1/2 teaspoon lemon zest; 1/4 teaspoon chili flakes; 3 cloves garlic; A few sprigs fresh thyme; A few sprigs fresh oregano

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I absolutely adore this Easy Cast Iron Flank Steak with Chimichurri Butter Recipe because it delivers restaurant-quality flavor right from my own kitchen, and it never fails to impress everyone at the dinner table. The combination of a perfectly seared flank steak with a vibrant, herbaceous chimichurri butter just feels like a celebration of bold, fresh flavors. It’s one of those dishes I turn to when I want something that’s both simple to prepare and deeply satisfying.

Why You'll Love This Easy Cast Iron Flank Steak with Chimichurri Butter Recipe

What really gets me about this recipe is the flavor profile. You get that amazing crust from the cast iron sear, which locks in all those rich, beefy juices, and then the chimichurri butter adds this gorgeous punch of brightness, freshness, and a little heat. The lemon zest and fresh herbs fold beautifully with the creamy butter, creating an irresistibly bold yet balanced bite.

Another reason I keep coming back to this Easy Cast Iron Flank Steak with Chimichurri Butter Recipe is how approachable it is. Sometimes, quick meals feel like compromises—but this one is different. It’s straightforward with pantry staples but tastes anything but basic. Whether I’m cooking for a casual weeknight or a special occasion, it’s always a hit. Plus, using a cast iron skillet makes the steak searing process really satisfying and foolproof, giving me a perfect crust every time.

Ingredients You'll Need

The image shows a large thin piece of raw red meat laid flat on a sheet of shiny aluminum foil that covers a metal tray. The meat is evenly sprinkled with coarse black pepper and light tan dried herbs, giving a speckled texture on the bright red surface. The edges of the meat are irregular, showing natural muscle lines and slight marbling. The aluminum foil wrinkles slightly around the meat, reflecting some light, and the background beneath the tray is mostly out of focus with a white marbled texture. photo taken with an iphone --ar 4:5 --v 7

For this recipe, I rely on simple, high-quality ingredients that each play a crucial role. The flank steak provides robust flavor and texture, while the kosher salt and garlic give it seasoning depth. The chimichurri butter is where the magic happens, with fresh herbs and lemon zest creating those unforgettable notes. Grape seed oil helps achieve a beautiful sear without overpowering the dish.

Quick Tip

All ingredient amounts are listed in the recipe card below

Grape seed oil: Perfect for high-heat searing, it won’t burn or overpower the steak’s flavor.
Flank steak (1.5-2 pounds): A lean cut that’s packed with flavor and perfect for quick cooking in a cast iron pan.
Morton kosher salt (2 heaping teaspoons): Essential for seasoning and creating a savory crust.
Pepper (1 teaspoon): Adds a mild heat that complements the beef without overwhelming it.
Granulated garlic (1 teaspoon): Gives a subtle but key garlic flavor that enhances the seasoning mix.
Salted butter (2 Tablespoons, room temp): Forms the rich base of the chimichurri butter, adding creaminess and depth.
Fresh parsley (1 Tablespoon, chopped): Bright herbaceous element that livens up the butter.
Lemon zest (½ teaspoon): Adds a zesty, citrus kick that brightens the whole dish.
Chili flakes (¼ teaspoon): Brings a gentle heat for complexity.
Garlic cloves (3): Fried to add mellow, golden garlic notes to the butter.
Fresh thyme & oregano (a few sprigs): Fried herbs that infuse the dish with earthy, aromatic flavors.

Directions

Step 1: In a small bowl, mix together the salted butter, chopped fresh parsley, lemon zest, and chili flakes. Set this chimichurri butter aside to let those flavors meld while you prepare the steak.

Step 2: In another small bowl, combine the Morton kosher salt, pepper, and granulated garlic. This seasoning mix will give your flank steak a punch of flavor and a delicious crust.

Step 3: Rub both sides of the flank steak thoroughly with the seasoning mix. Don’t be shy here—this is what builds the flavor foundation for your steak.

Step 4: Heat a generous amount of grape seed oil in a cast iron skillet over high heat until it’s shimmering and just about to smoke. This high heat will help you achieve that prized crust.

Step 5: Carefully place the steak in the center of the hot pan and resist the urge to move it. Let it sear undisturbed for 3-4 minutes until a deep, caramelized crust forms.

Step 6: Flip the steak and sear the other side for another 3-4 minutes. This helps lock in juices while continuing to build that perfect crust.

Step 7: Reduce the heat to medium and continue cooking. Use a thermometer and aim for an internal temperature of 125 to 130 degrees Fahrenheit for medium-rare, which usually takes about 1-2 minutes more per side depending on the thickness.

Step 8: While the steak cooks, add the garlic cloves and fresh herb sprigs (thyme and oregano) to the hot oil in the pan. Fry them gently until golden and fragrant, then remove and place them on a cutting board.

Step 9: Transfer the steak to a cutting board and let it rest for 5 to 10 minutes. Resting is crucial because it allows the juices to redistribute and keeps every bite juicy.

Step 10: Finely chop the fried herbs and garlic cloves, then mix them into your prepared chimichurri butter using a fork. This herb-infused butter is going to elevate your steak dramatically.

Step 11: Spread the chimichurri butter evenly over the rested steak, sprinkle with a little additional salt if you like, then slice the steak thinly against the grain for maximum tenderness. Serve immediately and prepare for rave reviews!

Servings and Timing

This Easy Cast Iron Flank Steak with Chimichurri Butter Recipe makes about 4 hearty servings. Prep time is really quick at around 5 minutes, considering the buttery chimichurri preparation. Cooking time is 15 minutes total, including searing and finishing the steak in the pan. Don’t forget to add 5 to 10 minutes resting time to ensure the steak stays juicy and tender. Altogether, expect about 20 to 25 minutes from start to finish. It’s a fantastic recipe for those who want something flavorful without a long wait.

How to Serve This Easy Cast Iron Flank Steak with Chimichurri Butter Recipe

A single cooked steak rests on a white plate over a white marbled surface. The steak has a dark brown seared crust with a slightly shiny texture, showing small bits of green herbs and minced garlic spread evenly on top. Some light brown drippings and small spots of oil surround the steak on the plate, adding a slight sheen and moisture effect. The overall look is simple and natural, focusing on the well-cooked meat. photo taken with an iphone --ar 4:5 --v 7

I love serving this steak sliced thin against the grain, which keeps it beautifully tender and easy to eat. It pairs wonderfully with fresh, crisp salads or grilled vegetables that add a nice textural contrast. A simple roasted potato or creamy mashed potatoes are also my go-to because they soak up any extra chimichurri butter so wonderfully.

For presentation, I like to arrange the sliced steak neatly on a warm serving platter, then dollop any remaining chimichurri butter over the top. Garnishing with some fresh parsley or a lemon wedge on the side really brightens the dish visually and adds a fresh note that guests appreciate.

When it comes to drinks, I often grab a sparkling water with fresh lime is a refreshing, non-alcoholic choice that cleanses the palate beautifully. This dish is versatile enough for family dinners, fancy gatherings, or relaxed weekends when I want something special without fuss.

Variations

If you want to shake things up, I’ve found that swapping flank steak for skirt steak works wonderfully too—it’s similarly lean and flavorful but cooks just a little quicker. For a gluten-free twist, this recipe is naturally compliant as long as you double-check your salt and spices for additives. Vegan friends might love trying a hearty grilled mushroom steak with a vegan butter chimichurri variant, using plant-based butter and skipping the meat entirely.

If you prefer a different flavor profile, consider adding smoked paprika or cumin to the seasoning mix for some warm depth or drifting toward a spicier chili flake dose for those who love heat. And while I always recommend cast iron for that perfect sear, grilling the flank steak outdoors over medium-high heat can lend a beautiful smoky flavor that feels perfect for summer cookouts.

Feel free to experiment with the herbs in the chimichurri butter too—cilantro or basil can bring interesting twists, just remember to maintain a balance with the lemon zest and garlic for that signature brightness.

Storage and Reheating

Storing Leftovers

I like to store any leftover Easy Cast Iron Flank Steak with Chimichurri Butter in an airtight container, preferably glass or BPA-free plastic, to keep the flavors sealed in. It keeps well in the refrigerator for up to 3-4 days. To preserve the texture and flavor, I always keep the steak slices separate from any extra butter or herbs and add those fresh when reheating.

Freezing

You can freeze leftover flank steak, although you’ll lose a little texture since steak tends to be best fresh. To freeze, slice the steak thinly and wrap tightly in plastic wrap or vacuum-seal it, then place in a freezer-safe bag. It should keep well for up to 2-3 months. Be sure to label the bag with the date so you don’t forget. When you’re ready to use it, thaw overnight in the refrigerator for best results.

Reheating

When reheating, I never microwave the steak directly as it can dry out fast. Instead, I gently warm slices in a hot skillet with a little bit of butter or oil to keep the meat moist and revive some of that crispy exterior. Adding a fresh dollop of chimichurri butter after heating brightens the flavor and restores richness. This method keeps the steak juicy and nearly as delicious as freshly cooked.

FAQs

What is the best way to get a perfect crust on flank steak?

I’ve found that using a hot cast iron skillet with grape seed oil and not moving the steak around during the initial sear is key. Let it develop a deep caramelized crust on each side before flipping. Patting the steak dry beforehand and seasoning generously also helps achieve that amazing crust.

Can I make the chimichurri butter ahead of time?

Absolutely! You can mix the chimichurri butter components up to a day in advance and keep it refrigerated. Just let it come to room temperature before serving so it’s spreadable and the flavors shine. It actually tastes more developed after resting.

How do I ensure my flank steak is tender?

Besides slicing against the grain, make sure you don’t overcook the steak. Flank steak is best enjoyed medium-rare to medium. Also, always let it rest after cooking so the juices redistribute. Using fresh seasoning and resting butter also helps tenderize the meat subtly.

Can I use a different type of butter for the chimichurri?

You can swap salted butter for unsalted if you prefer, just adjust the salt in the seasoning accordingly. For a dairy-free option, plant-based butters work nicely too. The key is to use a good quality butter or butter alternative with a creamy texture.

Is grape seed oil really necessary, or can I use another oil?

Grape seed oil is ideal because it has a high smoke point and neutral flavor, perfect for searing steak at high temperatures. You can substitute it with avocado oil or refined canola oil if needed, but avoid extra virgin olive oil as it burns too quickly for this method.

Conclusion

I hope you feel as excited as I do to try this Easy Cast Iron Flank Steak with Chimichurri Butter Recipe for yourself. It’s sincerely one of my favorite go-to recipes when I want big flavor without the fuss. The combination of a beautifully seared steak topped with herbaceous, zesty butter feels like an effortless gourmet experience every single time. Give it a try and enjoy every juicy, flavorful bite—I promise it will become one of your favorites too!

Easy Cast Iron Flank Steak with Chimichurri Butter Recipe

Why You'll Love This Easy Cast Iron Flank Steak with Chimichurri Butter Recipe