In a mixing bowl, combine all the marinade ingredients - vegetable oil, lime juice, minced garlic, soy sauce, Worcestershire sauce, cumin, chili powder, smoked paprika, crushed red pepper flakes, salt, and black pepper. Whisk until well combined.

Place the sliced chicken or steak in a large resealable plastic bag or a shallow dish. Pour the marinade over the meat, ensuring it is evenly coated. Seal the bag or cover the dish and refrigerate for at least 2 hours, or preferably overnight, to allow the flavors to infuse.

Heat a large skillet or grill pan over medium-high heat. Once hot, add the marinated meat and cook until it is nicely seared and fully cooked through. Remove the meat from the pan and set it aside.

In the same skillet, add a drizzle of oil if needed, and then toss in the sliced bell peppers and onions. Sauté until they become tender and slightly charred, maintaining some crispness.

Warm the flour tortillas in the microwave or over low heat in a separate dry pan.

To serve, place a generous amount of the cooked fajita meat on a warmed tortilla, followed by the sautéed peppers and onions. Add any desired toppings, such as sour cream, guacamole, salsa, shredded cheese, cilantro, and sliced jalapeños.

Fold the tortilla over the filling, creating a fajita wrap, and repeat the process for the remaining fajitas.

Serve the Chili's fajitas hot with lime wedges on the side for an extra burst of flavor.