Heat the oil in a heavy-based saucepan. Add the onion, season and let it
soften for several minutes before adding the dried spices and sweating for a few minutes more. Add the peppers, season, cover and cook together for at
least 10 minutes or until softened before adding the chopped chilli and garlic.
Stir in the tomato purée until everything is coated, then pour in the
chopped tomatoes. Add the sugar, Tabasco, balsamic vinegar and about
100ml water. Season and stir to incorporate. Simmer for around 25–30
minutes, occasionally topping up with water if the sauce becomes too dry.
Drain and rinse the beans. Add to the pan and simmer for a further
15-20 minutes.
Meanwhile, divide each tortilla into 8 triangular pieces. Heat 150ml of the oil in a large frying pan over a medium heat. Lightly fry several of the tortilla pieces until golden before turning over and frying on the other side. Remove to a plate lined with kitchen paper and season immediately with sea salt.
Repeat the process until all the pieces are golden and crunchy. You may
need to add a little more oil about halfway through.
Just before serving, break the chocolate into small squares and stir into the chilli. The sauce will turn thick and glossy. Allow everything to amalgamate before serving.
Serve the chilli with chopped fresh coriander, sliced avocado, wedges of lime for squeezing and a stack of homemade tortilla chips.