Cut chicken into ½-1 inch pieces. Heat 1 Tbsp oil in a large frying pan on medium heat. Add chicken and cook for 15 minutes or until chicken is thoroughly cooked.
Slice onions and bell peppers and then cut into 2 inch pieces. Heat 1 Tbsp oil in small frying pan on medium heat. Add onions and bell peppers and cook until slightly browned (approx. 5 minutes)
Add lime, cumin, coriander and garlic powder to chicken and stir until thoroughly mixed.
While the chicken is cooking, make the guacamole. Scoop avocado out of the skin and smash with fork. Add onion powder, garlic powder, cumin, coriander and a splash of lime juice, stir until smooth.
Roughly chop lettuce and grate cheddar if desired.
Serve chicken, onion and bell peppers on warmed tortillas, topped with lettuce, salsa and guacamole (can also top with cheddar and sour cream if desired). Enjoy!