Preheat the oven to 180 degrees Celsius (or if you have an airfryer, you can use that instead).
Heat a pan on a medium heat and spray well with 1kcal spray.
Add your onion and garlic and sauté for 2-3 minutes until soft.
Add your chicken and sauté until cooked throughout and starting to colour on the outside.
Sprinkle on the taco/fajita seasoning and mix well.
Add your chopped tomatoes and bring to a simmer for 5 minutes stirring now and again.
Taste and season as required with the mixed herbs, salt and pepper.
Meanwhile, slice your peppers in half and remove the seeds (keep the stalks on).
Place the halved peppers on a baking tray and spray with 1 kcal spray.
Spoon your chicken and tomato mixture in to each half pepper with as much as you can fit in.
Top each pepper half with the grated cheese and bake or airfry for 15 minutes at 180 degrees Celsius.