Heat 1 tbsp olive oil in a skillet, add diced onion and bell peppers, and sprinkle with paprika. Cook on medium heat for a few of minutes and set aside.
Add 1 tbsp of olive oil to the same skillet and cook chicken with the fajita spice mix until it's cooked through and slightly browned. Set aside and dice.
Place one tortilla in a non-stick skillet. Sprinkle with cheese. Add chicken and peppers. Sprinkle generously with cheese and cover with another tortilla. When the bottom tortilla is browned, carefully turn to the other side and brown.