Marinade Preparation:

1. In a bowl, combine vegetable oil, lime juice, minced garlic, soy sauce, Worcestershire sauce, ground cumin, chili powder, salt, and pepper.
2. Place the skirt steak or chicken breast in a resealable plastic bag and pour the marinade over it.
3. Seal the bag and refrigerate for at least 1 hour to infuse the flavors into the meat.

Preparing the Fajita Fillings:

1. Heat a tablespoon of vegetable oil in a skillet over medium-high heat.
2. Sauté the sliced onions and bell peppers until they’re tender and slightly caramelized.
3. Remove them from the skillet and set them aside.

Cooking the Fajitas:

1. In the same skillet, heat another tablespoon of vegetable oil.
2. Remove the meat from the marinade, allowing excess marinade to drip off.
3. Cook the skirt steak or chicken breast in the skillet for about 4-6 minutes per side or until it reaches your desired doneness.
4. Transfer the cooked meat to a cutting board and let it rest for a few minutes.
5. Slice the meat into thin strips, ensuring it’s cut against the grain for maximum tenderness.

Assembling the Fajitas:

1. 1. Warm the tortillas either in a skillet or in the microwave.
   2. Place a few slices of the cooked meat on each tortilla.
   3. Top the meat with the sautéed onions and bell peppers.
   4. Add optional toppings like guacamole, sour cream, salsa, or shredded cheese.
   5. Fold the tortilla over the filling, tucking in the sides to create a neat bundle.