Preheat the oven to 200c/Gas mark 6, or the grill on its highest setting. Grease a baking dish with a little oil.
Heat the oil in a medium pan over a low heat and cook the onions and garlic for 10 minutes. Add the tomatoes, 200ml of cold water, the stock cube, chili, oregano and mince to the pan. Mix really well then simmer for 15 minutes. Once thickened, season well with salt. Set half the turkey mixture aside.
Place a little of the turkey into a tortilla. Add a little cheese, roll up and place in the prepared baking dish, then repeat until you’ve filled all eight tortillas. The tighter you can pack them in the dish, the better.
Spoon over the rest of the mince and the remaining cheese. Bake for 15 minutes to brown, or quickly brown under the grill. Serve with soured cream.