Heat the garlic infused oil in a large wok or frying pan and brown the chicken for a couple of minutes.
Combine all of the dry spices in a bowl and mix well.
Add to the pan, along with the mixed peppers, and stir so that the spices cover all of the ingredients. Cook for 10 minutes or so, until the chicken is cooked (I always cut a larger piece open to check they are cooked right through).
While the fajita filling is cooking, slice some iceberg lettuce, grate a dollop of lactose-free cheese, and warm up the tortillas in the microwave. Serve with creme fraiche (this is naturally lower in lactose) and create tasty chicken fajita wraps.