Beef Fajitas

Introduction

Beef fajitas hinge on a well-seasoned, properly rested steak sliced thin and served with charred peppers and onions—this recipe delivers that through a soy-and-lime marinade that works overnight and a high-heat grill finish. You’ll marinate the skirt steak for at least a few hours (or up to a day), grill it to a safe internal temperature, then finish the peppers and onions in a cast-iron skillet while the meat rests. Serve with tortillas, salsa, guacamole, and lime wedges for a weeknight dinner that tastes like restaurant fajitas.

Recipe Details

• Prep Time: 15 minutes
• Cook Time: 25 minutes
• Total Time: 40 minutes (plus 1–24 hours marinating time)
• Servings: 6–12

Ingredients

Marinade

• ½ cup olive oil
• ⅓ cup soy sauce
• Juice of 2 limes
• 1 tsp red pepper flakes
• ½ tsp freshly-ground cumin
• 4 green onions, chopped
• 3 Tbsp dark brown sugar

Fajitas

• 1 ea. (2.25 lb / 1 kg) inside skirt steak, cut into 3 equal pieces
• 1 Tbsp vegetable oil
• 4 small onions, wedged
• 2 small red and green bell peppers, sliced

Serving

• Tortillas
• Salsa fresca
• Chunky guacamole
• Lime wedges

Instructions

1. Combine olive oil, soy sauce, lime juice, red pepper flakes, cumin, green onion, and brown sugar in a blender. Blend until smooth.
2. Pour marinade into a gallon size zip-top plastic bag. Add skirt steak and seal, removing as much air as possible. Refrigerate for at least 1 hour, preferably 24 hours or more.
3. Remove steak from marinade and place down as close as possible to coals of a preheated charcoal grill. Cook one side until the internal temperature is 125°F (51°C). Flip and allow to cook until the internal temperature is at least 145°F (63°C) in the thickest part. These temperatures are enough to safely cook the meat, you may like it more well done.
4. Remove and cover immediately, allowing at least 3 minutes to rest. You may wish to immediately wrap tightly with aluminum foil and remove to a low heat area of the grill or a low heat oven to keep ready for less-than-immediate use.
5. Meanwhile, place a 9-10-inch (23-25 cm) cast-iron skillet down on the coals (or a stove).
6. Once pan has heated, toss sliced peppers and onions with vegetable oil. Place in the skillet and cook for at least 2-3 minutes. They should be cooked to a moderately soft state on high heat with some browning evident. A small amount of water can be added, and the pan covered, to partially steam the vegetables if desired. Remove and keep warm.
7. Slice steak as thinly as possible across the grain.
8. Serve fajitas with tortillas, salsa, guacamole, and lime wedges (see notes).

Variations

• Stovetop instead of grill: Use a cast-iron skillet or heavy stainless-steel pan over medium-high heat on your stove. Sear the steak pieces 3–4 minutes per side, monitoring the internal temperature with a meat thermometer. This works just as well if you don’t have grill access.
• Thicker pepper and onion slices: Cut them into thicker wedges or strips if you prefer more texture and less char. They’ll cook slightly longer (4–5 minutes) but remain firmer.
• Mushrooms and zucchini: Add sliced cremini mushrooms or thin zucchini rounds to the skillet alongside the peppers and onions for extra volume and umami depth.
• Shorter marinating time: If you’re short on time, marinate for just 1 hour instead of overnight. The flavor will be lighter, but the steak will still be tender and tasty.
• Corn tortillas instead of flour: Use warm corn tortillas for a firmer, more traditional texture. Warm them directly over the grill grate or in a dry skillet before serving.

Tips for Success

• Don’t skip the rest: After the steak reaches temperature, let it rest for a full 3 minutes covered. This allows juices to redistribute and keeps the meat tender when you slice it.
• Slice against the grain: Skirt steak has a visible grain direction. Slice perpendicular to it for maximum tenderness; slicing with the grain will leave the meat chewy.
• High heat for the vegetables: Use the hottest part of your grill or stove for the peppers and onions. You want browning and some char, not steaming. If they’re softening without color, increase the heat or reduce the cooking time.
• Keep the cast-iron skillet on the grill while prepping: Starting it on the coals while you finish the steak means it’s already hot when you add the vegetables, which cuts your total cooking time.
• Marinate overnight if your schedule allows: The flavor deepens significantly between 12 and 24 hours, and you’ll have one fewer task on the day you cook.

Storage and Reheating

Refrigerator: Store sliced steak and cooked vegetables in separate airtight containers for up to 3 days. The steak stays tender and the vegetables keep their texture better when not combined.

Freezer: The steak freezes well for up to 3 months in an airtight container. The vegetables become softer when thawed, so freeze them only if you’re willing to accept a change in texture.

Reheating: Warm sliced steak in a skillet over medium heat for 1–2 minutes per side, or in a 300°F oven covered with foil for 5 minutes. Reheat vegetables in a skillet on medium heat for 2–3 minutes, stirring occasionally. If reheating from frozen, thaw in the refrigerator overnight first.

FAQ

Can I use a different cut of steak?

Flank steak or sirloin work, though skirt steak is ideal because its loose grain structure absorbs the marinade deeply and becomes tender when sliced thin. Avoid very thick cuts like ribeye or strip steak, which won’t benefit as much from the long marinating time.

What if I don’t have a grill?

Use a cast-iron or heavy stainless-steel skillet on your stovetop over medium-high heat. Sear the steak pieces 3–4 minutes per side, checking internal temperature with a meat thermometer. The char won’t be as pronounced, but the cooking time and results are nearly identical.

How thin should I slice the steak?

Slice it as thin as practical without falling apart—about ¼ inch is ideal. Thinner slices are more tender and easier to wrap in tortillas; thicker slices will be chewier, especially with the longer marinade.

Can I marinate the steak in the refrigerator instead of the freezer?

Yes, the recipe calls for refrigerator storage. A gallon-size zip-top bag in the fridge is the standard method. A freezer is not needed unless you’re storing it for longer than 1 day before cooking.