In a mixing bowl, combine the ground cumin, chili powder, onion powder, garlic powder, smoked paprika, salt, and crushed red pepper flakes. Add the chicken breasts and drizzle with 1 tablespoon of olive oil and the lime juice. Toss to coat the chicken evenly and let it marinate for at least 20 minutes. For maximum flavor, consider marinating for up to 2 hours in the refrigerator.
While the chicken is marinating, slice your bell peppers and red onion. Mince the garlic and set everything aside.
Heat 1 tablespoon of olive oil in a large skillet over medium-high heat. Once hot, add the marinated chicken breasts. Cook for about 5-7 minutes on each side or until the chicken is golden brown and cooked through (internal temperature should reach 165°F). Remove the chicken from the skillet and let it rest for a few minutes before slicing it into strips.
In the same skillet, add the sliced bell peppers, red onion, and minced garlic. Sauté for about 5-6 minutes until the vegetables are tender and slightly charred. Feel free to add a pinch of salt for extra flavor.
Add the sliced chicken back into the skillet with the sautéed vegetables. Toss everything together to combine. Warm the flour tortillas either in the microwave or on a dry skillet for a few seconds on each side until pliable.
To serve, layer the chicken and vegetable mixture onto each tortilla. Top with sour cream, guacamole, black beans, and salsa as desired. Garnish with fresh parsley for a pop of color.