Chicken chimichangas

Name: Chicken chimichangas
Ingredients: 3 tbsp vegetable oil, plus 60ml (if frying rather than baking); 5 skinless and boneless chicken thigh fillets, or about 300g leftover cooked chicken; ½ onion, chopped; 1 small red pepper, roughly chopped; 100g green chillies from a jar, finely chopped; 85g Monterey Jack cheese, grated plus extra for serving; ½ tsp garlic powder; ½ tsp ground cumin; ½ tsp chipotle chilli powder; 6 large flour tortillas; 400g can refried beans (optional); 240ml red enchilada sauce; soured cream and a handful of chopped coriander, to serve