Quick Recipe Version (TL;DR)
Quick Ingredients
- 1 1/2 lb (680 g) flank steak
- 1/4 cup (60 ml) fresh lime juice
- 2 tbsp (30 ml) olive oil
- 3 garlic cloves, minced
- 1 1/2 tsp ground cumin
- 1 tsp chili powder
- 1 1/4 tsp kosher salt, divided
- 1/2 tsp black pepper
- 1 large yellow onion, sliced
- 3 bell peppers (any colors), sliced
- 1 1/2 tbsp (22 ml) neutral oil (for vegetables)
- 8 small flour tortillas (6-inch)
- Toppings: lime wedges, chopped cilantro, salsa or pico de gallo, sour cream, shredded cheese, sliced avocado
Do This
- 1. Mix lime juice, olive oil, garlic, cumin, chili powder, 1 tsp salt, and pepper; marinate steak 45 minutes (up to 8 hours).
- 2. Preheat grill to high (450–500°F / 232–260°C); oil the grates.
- 3. Toss onions and peppers with neutral oil and remaining 1/4 tsp salt.
- 4. Grill steak 4–6 minutes per side to 130–135°F (54–57°C) for medium-rare; rest 10 minutes.
- 5. Grill onions and peppers 8–12 minutes, turning often, until charred-tender; keep warm.
- 6. Warm tortillas 30–45 seconds per side on the grill.
- 7. Slice steak thinly against the grain; serve with vegetables and toppings for DIY fajitas.
Why You’ll Love This Recipe
- Big fajita flavor with a simple lime-garlic-cumin marinade that works with pantry spices.
- Char-grilled steak and vegetables for that restaurant-style smokiness at home.
- Easy to scale up for a crowd, and everyone builds their own fajitas.
- Fast cooking time once the grill is hot.
Grocery List
- Meat: 1 1/2 lb (680 g) flank steak
- Produce: limes (3–4), garlic, 1 large yellow onion, 3 bell peppers, cilantro, avocado (optional)
- Dairy: sour cream, shredded Monterey Jack (or crumbled queso fresco)
- Pantry: olive oil, neutral oil (canola/avocado), ground cumin, chili powder, kosher salt, black pepper, flour tortillas, salsa or pico de gallo, hot sauce (optional)
Full Ingredients
Flank Steak + Marinade
- 1 1/2 lb (680 g) flank steak
- 1/4 cup (60 ml) fresh lime juice (from about 2–3 limes)
- 2 tbsp (30 ml) olive oil
- 3 garlic cloves, finely minced (about 1 tbsp)
- 1 1/2 tsp ground cumin
- 1 tsp chili powder
- 1 tsp kosher salt
- 1/2 tsp freshly ground black pepper
Grilled Peppers and Onions
- 1 large yellow onion, cut into 1/2-inch slices (about 2 1/2 cups / 250 g)
- 3 bell peppers (any colors), seeded and sliced into 1/2-inch strips (about 4 cups / 400 g)
- 1 1/2 tbsp (22 ml) neutral oil (canola or avocado oil)
- 1/4 tsp kosher salt
- Optional: 1/4 tsp ground cumin (for extra warmth)
Tortillas and Toppings (Choose Your Favorites)
- 8 small flour tortillas (6-inch)
- 1 lime, cut into wedges (plus extra wedges, if you like)
- 1/2 cup (120 g) sour cream
- 1 cup (240 g) salsa or pico de gallo
- 1 cup (100 g) shredded Monterey Jack or cheddar (or 3/4 cup / 90 g crumbled queso fresco)
- 1/2 cup (15 g) chopped fresh cilantro
- 1 avocado, sliced (optional)
- Hot sauce, to taste (optional)
Step-by-Step Instructions
Step 1: Make the lime-garlic-cumin marinade
In a medium bowl, whisk together the lime juice, olive oil, garlic, cumin, chili powder, kosher salt, and black pepper until well combined.
Tip: This marinade is intentionally bold. It seasons the steak and also helps it stay juicy over high heat.
Step 2: Marinate the flank steak
Place the flank steak in a gallon zip-top bag or a shallow baking dish. Pour in the marinade and turn the steak to coat well.
Refrigerate for 45 minutes (or up to 8 hours). If marinating longer than 1 hour, flip the steak once or twice so it marinates evenly.
About 20 minutes before grilling, pull the steak from the refrigerator so it can take the chill off (this helps it cook more evenly).
Step 3: Preheat the grill (and set up for great char)
Preheat a gas grill to high heat (450–500°F / 232–260°C). If using charcoal, build a two-zone fire with a hot side for searing and a cooler side for finishing.
Clean the grates, then lightly oil them by wiping with a folded paper towel dipped in a little neutral oil (use tongs).
Step 4: Prep the peppers and onions
In a large bowl, toss the sliced onion and bell peppers with the neutral oil and 1/4 tsp kosher salt (and the optional 1/4 tsp cumin if using).
If you have a grill basket, it’s perfect here. If not, keep the slices larger so they’re easy to turn and don’t fall through the grates.
Step 5: Grill the flank steak
Remove the steak from the marinade and let any excess drip off. Place it on the hot grill and cook, covered, for 4–6 minutes per side, until nicely charred and an instant-read thermometer reads:
- 130–135°F (54–57°C) for medium-rare
- 140–145°F (60–63°C) for medium
Transfer the steak to a cutting board and rest for 10 minutes. Resting keeps the juices in the meat and makes slicing easier.
Step 6: Grill the onions and peppers until charred-tender
While the steak rests, grill the onions and peppers. If using a grill basket, place it over high heat and cook, tossing every couple minutes, for 8–12 minutes until softened with browned edges.
If grilling directly on the grates, cook the onions and peppers in a single layer and turn with tongs every 2–3 minutes, aiming for char marks and tender-crisp texture.
For extra “sizzle” at the table, you can transfer the hot vegetables to a preheated cast iron skillet (on the grill or stovetop) for 1–2 minutes, stirring, just before serving.
Step 7: Warm the tortillas
Warm tortillas on the grill over medium heat for 30–45 seconds per side, just until pliable and lightly toasted.
Stack them in a clean kitchen towel to keep warm.
Step 8: Slice the steak thin and serve DIY fajitas
Identify the direction of the grain (the long muscle lines). Slice the steak thinly across the grain at a slight diagonal. For extra-tender bites, keep slices about 1/8 to 1/4 inch thick.
Serve sliced steak with the grilled onions and peppers, warm tortillas, and toppings (lime wedges, cilantro, salsa, sour cream, cheese, avocado). Let everyone build their own fajitas.
Pro Tips
- Don’t skip the rest: Resting the steak for 10 minutes makes it noticeably juicier and easier to slice thin.
- Slice against the grain: This is the biggest key to tender flank steak. Thin slices help, too.
- Use a thermometer: Pulling at 130–135°F (54–57°C) gives you flavorful char without drying out.
- Get better char, less sticking: Preheat well, clean the grates, and oil them lightly right before grilling.
- Keep tortillas warm: Wrap in a towel (or foil) so they stay soft while everyone serves themselves.
Variations
- Skillet fajitas (no grill): Sear steak in a cast iron skillet over medium-high heat for 4–6 minutes per side; sauté peppers and onions for 10–12 minutes until browned and tender.
- Spicier: Add 1/2 tsp chipotle powder or 1 minced jalapeño to the marinade, and serve with hot sauce.
- Lower-carb: Swap tortillas for lettuce wraps and add extra grilled veggies plus avocado.
Storage & Make-Ahead
Refrigerate: Store leftover steak and vegetables in separate airtight containers for up to 4 days.
Reheat: Warm steak gently in a skillet over medium-low heat with a splash of water or broth for 2–4 minutes (avoid high heat, which can toughen it). Reheat vegetables over medium heat for 3–5 minutes.
Make-ahead: Mix the marinade up to 3 days ahead and refrigerate. Slice peppers and onions up to 24 hours ahead. You can also grill everything ahead and reheat for a quick weeknight fajita night.
Freeze: Freeze cooked sliced steak (without vegetables) for up to 2 months. Thaw overnight in the fridge before reheating.
Nutrition (per serving)
Approximate, assuming 1/4 of the steak and vegetables, 2 small flour tortillas, and moderate toppings: 650 calories, 38 g protein, 55 g carbohydrates, 28 g fat, 6 g fiber, 1200 mg sodium.
