If you’re looking for a simple and delicious meal, learning how to cook a flank steak in oven is a fantastic skill. This method is surprisingly easy and delivers a tender, flavorful result perfect for weeknights or company.
Flank steak is a lean, budget-friendly cut known for its bold beefy flavor. While it’s often grilled, your oven is a reliable tool for cooking it perfectly, especially when you use a quick sear and finish method. This guide will walk you through every step, from choosing the best steak to slicing it correctly.
How to Cook a Flank Steak in Oven
This is the primary method we recommend for the best texture and taste. It involves searing the steak on the stove first to create a flavorful crust, then finishing it in the oven to your desired doneness. This gives you the best of both cooking worlds.
What You’ll Need
- 1 flank steak (1.5 to 2 pounds)
- 1-2 tablespoons high-smoke-point oil (like avocado, canola, or vegetable oil)
- Salt and freshly ground black pepper
- An oven-safe skillet (cast iron or heavy stainless steel is ideal)
- Meat thermometer (highly recommended for perfect results)
- Tongs
- Cutting board
Step-by-Step Instructions
1. Prepare the Steak
Take the steak out of the refrigerator about 30 minutes before cooking. Letting it come closer to room temperature helps it cook more evenly. Pat it completely dry with paper towels. This is crucial for getting a good sear. Generously season both sides with salt and pepper. You can also add other dry rubs at this stage if you like.
2. Preheat Your Oven and Pan
Place your oven-safe skillet on the stove over medium-high heat. Let it get hot for a few minutes. Preheat your oven to 400°F (200°C). Having both the pan and oven hot is key to the process.
3. Sear the Steak
Add the oil to the hot skillet. It should shimmer. Carefully place the flank steak in the pan. It should sizzle immediately. Let it sear, without moving it, for 3-4 minutes until a deep brown crust forms. Use your tongs to flip it and sear the other side for another 3-4 minutes.
4. Transfer to the Oven
Immediately move the entire skillet from the stove into your preheated oven. For a medium-rare finish, this usually takes 5 to 8 minutes. The exact time depends on your steak’s thickness and your oven. This is where a meat thermometer is your best friend.
5. Check for Doneness
Insert the meat thermometer into the thickest part of the steak. For medium-rare, aim for 130-135°F (54-57°C). For medium, aim for 140-145°F (60-63°C). Remember, the temperature will rise about 5 degrees while the steak rests. Avoid overcooking, as flank steak can become tough.
6. Rest the Steak
This is the most important step for a juicy steak! Transfer the cooked steak to a cutting board. Loosely tent it with a piece of aluminum foil. Let it rest for a full 10 minutes. This allows the juices, which have been driven to the center, to redistribute throughout the meat.
7. Slice Against the Grain
Look closely at the steak. You will see long muscle fibers running lengthwise—this is the “grain.” Using a sharp knife, slice the steak thinly, perpendicular (across) these fibers. Slicing against the grain shortens the muscle fibers, making each piece much more tender to eat.
Alternative Oven-Only Method (Broiling)
If you don’t have an oven-safe skillet, you can use your oven’s broiler. Place an oven rack about 4-6 inches from the broiler element and preheat the broiler on high. Place the seasoned steak on a broiler pan or a wire rack set inside a baking sheet. Broil for 5-7 minutes per side, checking with a thermometer, until it reaches your desired doneness. Watch it closely to prevent burning.
Marinating for Maximum Flavor and Tenderness
A good marinade can add incredible flavor and help tenderize the lean flank steak. An acidic component (like vinegar, citrus juice, or wine) and oil are the base.
- Simple Marinade Recipe: Whisk together 1/3 cup soy sauce, 1/4 cup olive oil, 2 tablespoons red wine vinegar, 2 cloves minced garlic, and 1 tablespoon honey.
- Place the steak and marinade in a sealed bag or shallow dish. Refrigerate for at least 2 hours, or up to 12 hours (overnight is great).
- Before cooking, remove the steak from the marinade and pat it very dry. Discard the used marinade.
Tips for the Best Oven-Cooked Flank Steak
- Don’t Skip the Rest: Rushing this step means losing precious juices onto your cutting board.
- Invest in a Thermometer: It takes the guesswork out and guarantees perfect results every single time.
- Sharpen Your Knife: A dull knife will tear the meat instead of slicing it cleanly.
- Letting the steak sit out before cooking is helpful, but don’t leave it out for more than an hour for food safety reasons.
- If your steak has a thick layer of fat on one edge, you can trim a little off, but some fat adds flavor during cooking.
What to Serve With Flank Steak
Flank steak is wonderfully versatile. Here are some classic pairing ideas:
- Starches: Garlic mashed potatoes, roasted potato wedges, or cilantro-lime rice.
- Vegetables: A simple green salad, roasted asparagus, or sauteed mushrooms and onions.
- Sauces: A pat of herb butter melting on top, chimichurri sauce, or a creamy horseradish sauce complements it beautifully.
Storing and Reheating Leftovers
Store leftover sliced steak in an airtight container in the refrigerator for up to 3-4 days. To reheat, avoid the microwave if you can, as it will overcook the meat. Instead, gently warm slices in a skillet over low heat with a splash of broth or water, or enjoy them cold in salads or sandwiches.
Common Mistakes to Avoid
- Not Drying the Steak: Moisture on the surface creates steam and prevents a proper sear.
- Moving the Steak Too Soon: Let it develop that crust in the hot pan before flipping.
- Skipping the Rest: We can’t stress this enough—it makes a huge difference.
- Slicing With the Grain: This will result in a chewy, stringy texture no matter how well you cooked it.
- Overcooking the steak is the fastest way to make it tough and dry. Use that thermometer.
FAQ Section
What is the best temperature to cook flank steak in the oven?
For the sear-and-finish method, a 400°F (200°C) oven is ideal. For broiling, use your oven’s high broil setting. The final internal temperature is more important: 130-135°F for medium-rare, 140-145°F for medium.
How long should you cook flank steak in the oven?
After searing, a 1.5-inch thick flank steak usually needs 5-8 minutes in a 400°F oven to reach medium-rare. Always use a meat thermometer to be sure, as cooking times can vary.
Do you have to marinate flank steak before baking?
No, it’s not required. A simple seasoning of salt and pepper still produces a tasty steak. However, marinating does add extra flavor and can help tenderize the meat a bit more, which many people prefer.
Why is my flank steak tough and chewy?
The three most common reasons are: 1) It was overcooked, 2) It wasn’t rested before slicing, or 3) It was sliced with the grain instead of against it. Avoiding these mistakes will give you a much more tender result.
Can I cook frozen flank steak in the oven?
It’s not recommended. Cooking from frozen will lead to uneven cooking—the outside will be overdone before the inside is thawed. For best results, thaw the steak fully in the refrigerator first.
What’s the difference between flank steak and skirt steak?
They are similar but different cuts. Flank steak is wider, thicker, and has a more uniform shape. Skirt steak is longer, thinner, and has a more pronounced grain. Both are great for marinating and need to be sliced against the grain, but cooking times may vary slightly.
Mastering how to cook a flank steak in oven opens up a world of easy, impressive meals. With these simple techniques—a hot sear, a reliable thermometer, proper resting, and slicing against the grain—you’ll consistently achieve a delicious and tender steak that rivals any restaurant version. The next time you see a good flank steak at the market, you’ll know exactly what to do with it.