Flank steak is a lean, flavorful cut of beef that can be a delicious option for cast iron cooking. When cooked correctly in a well-seasoned cast iron skillet, flank steak develops a lovely sear and caramelization that gives it plenty of flavor. The key is knowing how to prepare flank steak properly for cast iron to get optimal results.
What is Flank Steak?
Flank steak comes from the belly muscles of a cow. It is a relatively long and flat cut of meat that sits just below the loin. Flank steak has a distinct grain running lengthwise and is moderately tender when cooked quickly over high heat. It has a robust beefy flavor when seasoned simply with just salt and pepper.
Since flank steak is a leaner, tougher cut, it can become chewy and tough if overcooked. The best way to cook flank steak is fast and hot, either grilled or seared in a skillet, to medium rare doneness. This preserves moisture and gives you tender, sliceable steak. Flank steak is not well suited for slow cooking methods like braising.
Benefits of Cooking Flank Steak in Cast Iron
Cast iron skillets provide several advantages when cooking flank steak:
- High heat retention – Cast iron gets screaming hot and holds heat well, perfect for getting a hard sear on flank steak.
- Natural non-stick surface – A well-seasoned cast iron skillet has a natural non-stick patina ideal for getting a good crust on the meat.
- Promotes browning – The pores of cast iron absorb oil, leading to enhanced browning and caramelization on the steak surface.
- Imparts flavor – Any seasoning or oil on the cast iron infuses the steak with extra flavor.
- retains heat – Cast iron stays hot even when steak is added, preventing temperature drops that can lead to gray meat.
By taking advantage of cast iron’s properties, you can achieve restaurant-quality results cooking flank steak at home. The high heat helps develop that crusty exterior while keeping the inside tender and juicy.
How to Cook Flank Steak in Cast Iron
Follow these steps for foolproof flank steak cooked to perfection in cast iron:
- Pat the steak dry and season generously with salt at least 40 minutes before cooking. This gives time for the salt to penetrate and seasoning the meat.
- Allow steak to come to room temperature before cooking, about 30 minutes.
- Heat your cast iron skillet over medium-high heat until very hot. For a 12 inch skillet, heat for 4-5 minutes.
- Add just enough high smoke point oil to coat the bottom, like avocado oil. Allow to shimmer.
- Sear steak for 2-3 minutes per side, pressing down gently with spatula, until nicely browned.
- Flip steak and sear 2nd side for another 2-3 minutes until browned.
- Check temperature with instant read thermometer, removing at 125°F for medium rare.
- Rest steak at least 5 minutes before slicing against the grain into thin slices.
Always let your steak rest after cooking – this allows juices to redistribute so they don’t leak out when you cut into it. Resist the urge to keep flipping the steak – just sear it well on both sides.
Cast Iron Steak Tips
- Dry steak well before searing – this promotes browning.
- Use metal spatula to press steak down into pan – prevents curling up.
- Flip only once during cooking for best crust.
- Let pan reheat between batches if cooking multiple steaks.
- Add herbs, garlic, or butter to pan after cooking to baste steak.
- Don’t move steak around, just sear in place for best browning.
What to Look for in Cast Iron for Steak
To get the most out of cooking flank steak, choose the right cast iron skillet:
- 10-12 inch skillet – Large enough to sear steak evenly over high heat.
- Pre-seasoned – Look for pre-seasoned cast iron so steak won’t stick.
- Heavy-duty – Heavier cast iron retains heat best for searing.
- Smooth surface – Enameled or machined surface is ideal for steaks.
Avoid lighter weight imported cast iron that may not retain high heat. New unseasoned cast iron works but requires thorough seasoning first to prevent sticking.
Best Flank Steak Marinades
Marinating flank steak is a great way to infuse extra flavor. The marinade also tenderizes the meat. Some top options include:
Soy Sauce Marinade
A simple Asian-inspired marinade great for grilling or pan searing. Marinate for 1-2 hours.
- 1/2 cup soy sauce
- 1/4 cup honey
- 2 tablespoons rice vinegar
- 1 tablespoon toasted sesame oil
- 2 cloves garlic, minced
- 1 teaspoon grated ginger
Chimichurri Marinade
For incredible Argentinian-style flavor. Let marinate 4-12 hours.
- 1 cup packed cilantro leaves
- 1 cup packed parsley leaves
- 1/4 cup olive oil
- 3 tablespoons red wine vinegar
- 4 cloves garlic
- 1 shallot, chopped
- 1 tablespoon oregano
- 1/2 teaspoon red pepper flakes
- 1/2 teaspoon salt
Teriyaki Marinade
Easy to make teriyaki marinade that enhances flank steak’s flavor. Marinate 30-60 minutes.
- 1/2 cup soy sauce
- 1/4 cup honey
- 2 tablespoons rice vinegar
- 2 cloves garlic, minced
- 1 teaspoon ground ginger
- 1/4 teaspoon black pepper
Recipe: Cast Iron Steak Fajitas
This easy cast iron flank steak recipe results in fajitas packed with Mexican flavor. The steak gets seared to perfection.
Ingredients
- 1 1/2 lbs flank steak
- 1 lime, juiced
- 1/4 cup olive oil
- 3 cloves garlic, minced
- 1 teaspoon chili powder
- 1 teaspoon cumin
- 1 teaspoon oregano
- 1 red bell pepper, sliced
- 1 onion, sliced
- 8-12 flour tortillas
- Toppings like salsa, guacamole, cheese, etc.
Instructions
- Combine lime juice, olive oil, garlic, chili powder, cumin and oregano. Pour over steak and marinate for 1-2 hours.
- Remove steak from marinade and pat dry. Season with salt. Let come to room temp 30 minutes.
- Heat cast iron skillet over medium-high heat until very hot, about 4 minutes.
- Add oil and steak. Sear 2-3 minutes per side until browned and 125°F for medium rare.
- Transfer to plate and tent with foil to rest 5 minutes.
- Add bell pepper and onion to skillet. Cook until tender, stirring occasionally.
- Slice steak against the grain into thin strips.
- Serve steak and veggies with warm tortillas and toppings.
The sizzling hot cast iron really brings out the flavors of the fajita marinade. Slice the rested steak nice and thin across the grain for most tenderness. Pile everything into warm tortillas for an amazing homemade taco night!
Common Questions
Is flank steak better pan-fried or grilled?
Both grilling and pan frying are excellent, high-heat cooking methods for flank steak. Grilling imparts a lovely char while pan frying in cast iron gives unmatched sear and crust. It comes down to personal preference.
What is a good substitute for flank steak?
If flank steak is unavailable, skirt steak is the best substitute. Other good options include hanger steak, flat iron steak, or top round steak. All are fairly thin, moderate tenderness cuts suitable for high heat cooking.
Is flank steak supposed to be chewy?
Properly cooked flank steak should not be chewy. Chewiness results from overcooking beyond medium rare doneness. Always slice steak thinly across the grain after cooking to shorten muscle fibers for tenderness.
Can you braise or slow cook flank steak?
Flank steak has a loose grain and becomes unpleasantly stringy and chewy with low, slow cooking. It’s best suited for high heat fast cooking methods only like grilling, broiling, pan searing and stir frying.
What is the best way to reheat leftover flank steak?
The best way to reheat leftover flank steak is in a hot cast iron skillet or non-stick pan. Quickly sear steak about 1 minute per side just until heated through. This gives leftover steak new life!
Conclusion
Flank steak is a near-perfect choice for cooking in cast iron. Taking advantage of cast iron’s heat retention and non-stick surface results in flank steak with an unbeatable sear and juicy, tender interior when cooked to no more than medium rare. Pound for pound, flank steak delivers big beefy flavor. With the right cut, seasoning, and cooking technique, you can achieve restaurant-quality results in your own kitchen.