In a mixing bowl, combine 2 tablespoons olive oil, 1 teaspoon chili powder, 1 teaspoon cumin, 1 teaspoon paprika, 1 teaspoon salt, 1/2 teaspoon black pepper, and 1 lime juice to prepare the marinade.

Add the 1 pound flank steak or chicken breast to the marinade and coat thoroughly. Let it sit for at least 15 minutes to absorb flavors.

Heat the skillet over medium-high heat. Once hot, add the marinated meat and cook for about 5-7 minutes per side, until cooked through and nicely charred.

Remove the cooked meat from the skillet and let rest for 5 minutes.

While resting, add sliced bell pepper and onion to the same skillet and sauté for about 4-5 minutes until tender.

Slice the rested meat against the grain into thin strips.

Add sliced meat back into the skillet with vegetables and cook together for 1-2 minutes to meld flavors.

Warm tortillas in a separate pan or microwave.

Spoon the meat and vegetable mixture onto each tortilla.

Top with optional toppings like avocado, salsa, cheese, sour cream, and cilantro.