Slice chicken breast in half so you have 4 cutlets.
Season chicken with salt, cumin, garlic powder, oregano and black pepper.
Lightly spray a skillet on medium heat with oil or if using a grill, grill chicken until cooked on both sides, about 2 minutes on each side.
Remove from heat and cut chicken into strips, set aside.
To the skillet, add 1 tbsp oil and cook onions and peppers, season with salt and pepper.
Cook about 2 minutes, add garlic and continue cooking until vegetables are soft being careful not to burn the garlic. When cooked, set aside.
Heat skillet on medium heat and lightly spray with oil. Add tortilla, top with cheese, chicken, onions, peppers, and pico de gallo or avocado-mango salsa. Top with the other tortilla.
Cheese should be melted and the bottom of the tortilla should be golden brown. Put a plate on top of the quesadilla to flip it over onto the plate. Then slide the other side onto the skillet.
Cook another minute and remove with a spatula. Cut into wedges and serve with sour cream if you wish.