Juicy Marinated Flank Steak Recipe

This marinated flank steak is a flavorful, low-carb main that’s quick to cook and perfect for keto meal prep. It shines in fajitas, tacos, breakfast burritos, salads, and bowls — any time you want bold Mexican-inspired flavor with tender, juicy beef.

Marinated Flank Steak

Flank steak is a lean, economical cut that benefits greatly from a good marinade. The right mix of acid, oil, aromatics, and spices tenderizes the meat while infusing it with flavor. This transforms an affordable cut into a meal that’s elegant enough for guests and practical for weekly meal prep.

The steak cooks quickly — about 12 minutes on a hot grill or skillet — but the flavor and texture depend on allowing time for the marinade to work. You can marinate for a short time for flavor, or overnight for maximum tenderness.

Key Ingredients for the Marinade

Below is an overview of the ingredients used to make a bright, savory marinade that pairs especially well with fajitas and taco-style dishes. Exact measurements and the full recipe are included in the recipe card further down.

• Flank steak — a 1.5 pound cut works well
• Steak marinade (store-bought or your favorite homemade blend)
• Olive oil
• Fresh lime juice
• Minced garlic
• Seeded and chopped jalapeño
• Chopped red onion
• Fajita seasoning (a homemade blend is recommended)

How the Marinade Tenderizes

Marinades serve two main purposes: flavor and tenderizing. For lean cuts like flank steak, an acidic component such as lime juice helps break down connective tissue, producing a more tender bite. Enzyme-rich fruits can also tenderize, but for this recipe lime juice complements the Mexican-style flavors while contributing to texture.

How long to marinate depends on what you want: a short soak will add surface flavor, while several hours or overnight allows the acid to penetrate and soften the meat.

Recommended Marinating Times

• Quick flavor: 30 minutes — good if you’re short on time
• Tender and flavorful: 2 to 12 hours — 12 hours is ideal for best texture
• Maximum: up to 24 hours — avoid longer, as too much acid can make the texture mushy

How to Cook Marinated Flank Steak

This method is quick enough for a weeknight but yields restaurant-quality results. Combine your marinade ingredients in a large resealable bag or container, add the flank steak, and ensure the meat is well coated. If the steak isn’t fully submerged, turn it occasionally so all sides absorb the flavors. Marinate between 30 minutes and 24 hours.

Tip for leftovers and meal prep: Reserve a portion of the marinade before adding raw meat, or make an extra batch. Reheating sliced steak with a little reserved marinade keeps it moist and flavorful.

When ready to cook, preheat a skillet, griddle, or grill to high (about 400°F). Sprinkle the fajita seasoning over the least fatty side of the steak, place the steak fatty-side down, and sear for about 6 minutes. Flip and cook another 5–6 minutes, or until the internal temperature reaches your desired doneness. Allow the steak to rest before slicing.

Doneness Temperatures

Use an instant-read thermometer for best results. Remember the internal temperature will rise a few degrees while the steak rests.

• Medium Rare: 135°F (57°C)
• Medium: 145°F (63°C)
• Medium Well: 150°F (66°C)
• Well Done: 160°F (71°C)

Why Rest Steak Before Cutting

Letting steak rest after cooking keeps it juicy. During cooking, the meat’s juices move toward the center; resting lets those juices redistribute, so they remain inside the steak rather than spilling onto the plate. A rested steak will be moist and flavorful through every bite.

How to Slice Flank Steak

For the most tender slices, cut the steak against the grain. Look for the long white lines of muscle fibers and slice perpendicular to them. For attractive, tender pieces, slice at a slight diagonal (about 45 degrees) across the grain.

Storing and Reheating Cooked Steak

To keep cooked flank steak juicy when reheating, store sliced steak with a few tablespoons of reserved marinade. If storing a whole cooked steak, wrap it tightly in freezer paper and place it in an airtight bag to preserve juices. Refrigerate cooked steak for up to 3–4 days.

Reheat whole steaks in a 350°F oven covered, with a little reserved marinade, until the internal temperature reaches about 120–125°F. Reheat sliced steak the same way or in 20-second microwave bursts at 50% power; for crisp edges, quickly sear slices in a hot skillet.

Serving Suggestions

This marinated flank steak is versatile. Serve it in low-carb or keto-friendly tortillas, over cauliflower rice, in salads, or as the centerpiece of a taco bar. Pair with grilled peppers and onions, roasted tomatillo salsa, cilantro-lime cauliflower rice, or guacamole for a complete, flavor-packed meal.

Because the steak reheats and slices well, it’s ideal for meal prep: use it in fajitas, tacos, burritos, taco salads, or Mexican-style bowls.

Recipe Card — Marinated Flank Steak

Rating: 5 from 2 reviews

If you try this marinated flank steak, please leave a rating and share how you served it — it’s a flexible recipe that adapts easily to low-carb and keto meal plans.