Heat the oil in a frying pan. Cook the onions and the carrots for 5-10 minutes, until soft. Sprinkle in the chilli powder and cook for 1 minute more. Pour in the tomatoes, lentils, mixed beans and garlic and bring to the boil. Add the tomato purée and veg stock, then turn down the heat and simmer for 5-10 minutes, stirring occasionally, until thickened. Remove from the heat and season well.

Heat the grill to high. Lay each tortilla onto a board and fill with some of the chilli mixture, fold over the ends and roll up to seal. Place them into a ovenproof dish.

Sprinkle the cheese over the top of the enchiladas. Grill for a few minutes until the top is golden.