Preheat the oven to 180°C. Grease 4 oven-safe bowls or ramekins with oil and brush both sides of the tortillas with oil. Mould the tortillas into each bowl, roughly folding to fit into the shape of the bowl. Place bowls onto a tray and bake for 5 minutes until golden. They may seem slightly soft but cool completely in the bowls and they will crisp.
For the chilli con carne, heat the oil in a sauté pan over medium-high heat. Add the onion, capsicum and garlic and cook for 3–4 minutes until softened. Stir in the spices and cook for 1 minute more and then add the mince, break up any lumps with a fork, and season with salt and pepper. Cook for 2 minutes, then add the beans and tomatoes along with half a can of water. Cover with a lid and turn to low. Cook for 20-25 minutes until the stew is thick and rich.
For the salsa, combine the onion with the lime zest and juice and a pinch of salt. Marinate for 5 minutes before mixing in the avocado, chilli and coriander.
Place tortilla bowls on plates. Arrange lettuce leaves in bowls and fill with chilli con carne, sour cream, cheese and salsa.
