1. For the chilli, heat the oil in a heavy-based casserole, add the chorizo and fry gently for 5 minutes, until crisp. Set a sieve over a bowl and tip in the chorizo; reserve the excess oil in the bowl.
2. Pour ½ the oil back into the pan, turn up the heat and add the beef. Fry for 5 minutes, until golden brown and starting to crisp, then tip into the sieve with the chorizo.
3. Pour the remaining chorizo oil into the pan, add the onion and fry for 10 minutes, until soft and caramelised. Add the garlic and spices and cook for 2 minutes. Add the tomato purée and fry for 2–3 minutes, then pour in the chopped tomatoes and hot stock; bring to a simmer. Return the chorizo and beef to the pan, drop in the ancho chilli and simmer gently for 1 hour 30 minutes, stirring occasionally. Add the beans and cook for a further 30 minutes. Remove from the heat; season.
4. Preheat the barbecue for direct grilling. Grill the sausages for 6–8 minutes, until heated through and lightly charred, turning regularly. Move them to one side of the grill, then lightly toast the cut side of the rolls.
5. To assemble, spread the insides of each roll with American mustard (such as French’s Classic Mustard) and sit a sausage on top. Spoon over some of the chilli and serve with plenty of chopped onion and coriander.