Let’s get cooking.
Prepare the filling: cut the 650 g chicken into roughly 2 cm pieces. Peel and thinly slice the onion. Remove the pepper stalks and seeds, then slice the peppers into strips. Grate the 150 g cheddar.
Put the chicken in a bowl and toss with the 2 tbsp fajita seasoning, 1 tsp onion powder and 1 tsp garlic powder until evenly coated.
Heat the 1 tbsp oil in a large frying pan over medium-high heat. Add the chicken and onion, spread them out and cook for 6–8 minutes, stirring regularly. If they cannot fit in a shallow layer, work in as many batches as needed and divide the oil between them.
Add the prepared peppers and cook for another 4–5 minutes, stirring, until softened but still slightly firm. If cooking in batches, divide the peppers between them as well.
Stir in the 100 g spinach in handfuls until wilted. Check the chicken before serving: the centre of the thickest pieces should reach 75°C for 30 seconds with a food thermometer. Continue cooking if needed; the timings are a guide.
Warm the 8 tortillas following their packet instructions, then keep covered with a clean tea towel while you assemble the wraps.
Divide the filling and cheddar between the tortillas, leaving a border around the edges. Add the salsa if using. Fold in the sides, roll up firmly and serve, allowing 2 wraps per person.
