Slice the chicken breast or beef into thin strips. Season with fajita seasoning, salt, and black pepper. Set aside to marinate for at least 15 minutes.

Slice the Vegetables

While the meat is marinating, slice the bell peppers and onion into thin strips.

Cooking

Cook the Meat

In a large skillet, heat 1 tablespoon of olive oil over medium-high heat. Add the marinated chicken or beef strips and cook for about 5-7 minutes, or until fully cooked and slightly charred. Remove from the skillet and set aside.

Sauté the Vegetables

In the same skillet, add the remaining tablespoon of olive oil. Add the sliced bell peppers and onion. Sauté for about 5-6 minutes, or until they are tender and slightly caramelized.

Combine and Warm Tortillas

Return the cooked chicken or beef to the skillet with the sautéed vegetables. Toss everything together for about 2 minutes to combine flavors. Meanwhile, warm the tortillas in a separate pan or microwave.

Serving

Assemble the Fajitas

Serve the sizzling chicken or beef mixture with warm tortillas. Squeeze fresh lime juice over the top and add any optional toppings like sour cream, guacamole, cheese, and cilantro as desired.