Perfectly Seared Cast Iron Flank Steak with Garlic Butter Pan Sauce

Recipe Ingredients

These ingredients and suggested substitutions will give you a flavorful flank steak.

• Olive Oil (⅓ cup): Acts as the base for the marinade and helps the flavors penetrate. Avocado oil is a fine substitute.
• Soy Sauce (⅓ cup): Adds savory umami and salt. For a gluten-free option, use coconut aminos.
• Lime Juice (¼ cup): The acid helps tenderize and brightens the flavor. Lemon juice works interchangeably.
• Honey (¼ cup): Balances the savory and acidic components with natural sweetness. Maple syrup can be used instead.
• Minced Garlic (2 tablespoons): Fresh garlic gives a bold, aromatic boost. If needed, 1 teaspoon garlic powder can substitute.
• Flank Steak (2 pounds): A lean, flavorful cut that’s ideal for quick cooking. Choose an even-thickness piece for consistent results.
• Sea Salt and Black Pepper: Simple finishing seasonings that create a flavorful crust—don’t skip them.
• Fresh Parsley: Optional garnish to add freshness and color.

How To Make Flank Steak in Cast Iron

Whisk a quick marinade, let the steak absorb the flavors, sear in a hot cast iron pan, rest, and slice against the grain. Follow these steps for dependable results:

1. In a small bowl, whisk together the olive oil, soy sauce, lime juice, honey, and minced garlic until combined.
2. Place the flank steak in a lidded dish or a large gallon-size Ziploc bag.
   
3. Pour the marinade over the steak, ensuring it’s fully coated. Seal or cover and refrigerate for at least 2 hours or up to 24 hours for best flavor and tenderness.
4. When ready to cook, preheat a cast iron grill pan (or a regular cast iron skillet) over medium-high heat. Lightly spray or oil the pan to prevent sticking.
5. Remove the steak from the marinade and place it on a platter. Pat lightly if excess marinade is hanging on, then season both sides with sea salt and black pepper.
6. Sear the steak for about 6–8 minutes on the first side until a nice crust forms, then flip and cook another 6–8 minutes, adjusting time for desired doneness (130°F medium-rare, 140°F medium, 150°F medium-well). Use an instant-read thermometer for accuracy.
   
7. Transfer the steak to a cutting board and let it rest for about 10 minutes to allow juices to redistribute.
8. Slice thinly against the grain and serve immediately.

How to Cut Flank Steak

Slicing correctly is essential to tenderness. Here’s how to get tender, easy-to-chew pieces:

1. After resting, place the steak on a cutting board and identify the grain—the long muscle fibers running one direction. Slice perpendicular to those lines (against the grain).
2. Use a sharp knife and cut about 1/4-inch thick slices. Cutting against the grain shortens the muscle fibers, producing tender bites rather than chewy strands.

Pro tip: If the steak is very wide, slice it in half with the grain first, then rotate each piece and slice against the grain to make the process easier.