Prepare the marinade: In a medium bowl whisk all fajita seasoning/marinade ingredients. (Reserve about 2 tablespoons of marinade for the veggies.)
4 tablespoon cooking oil, 1 ½ tablespoon lime juice, 1 teaspoon ground cumin, ½ teaspoon cayenne pepper, ½ teaspoon salt, 2 cloves garlic, ¼ teaspoon black pepper
Marinate the steak: Place the steak strips and toss to coat with the marinade. Let the steak marinate for at least 30 minutes to 2 hours. If you're short on time, even a quick 30-minute marinate will work.
1 pound skirt flank, sirloin, or hanger steak
Marinate the vegetables: In a separate, small bowl toss the bell peppers and onions with the marinade. Cover and refrigerate for 30 in to an hour. Alternatively, sealable plastic bags can be used here as well.
3 red bell peppers, 1 medium brown onion
Cook: In a large skillet over medium-high heat, add cooking oil and once heated cook the veggies until softened but still crisp. About 5 minutes. Set aside.
Wipe the skillet if needed, add more oil and cook the steak strips for 5-6 minutes. They will cook very fast as they are small and cut into strips.
Return the veggies to the pan and combine everything. Taste for seasoning, drizzle with lime juice to taste right before serving.
Warm tortillas: Warm the flour tortillas or taco shells one by one in a separate dry pan until they begin to char (this will happen very fast, about 30 seconds per side on medium-high heat). Wrap them in foil to keep warm until ready to use.
4 tortillas, 1 bunch of fresh cilantro or parsley, ½-1 cup sour cream or creme Fraiche
Assemble and Serve: Serve steak fajita tacos with sour cream, lime wedges, fresh sliced green onions, fresh cilantro, more cayenne, and freshly cracked black pepper, avocados, shredded cheese.