Heat oil in a large saucepan and fry onion, garlic and capsicum until onions softens. Add Mexican spice and cumin and cook, stirring until fragrant.
Add undrained tomatoes, stock, beans and tomato paste and bring to the boil.
Reduce heat and simmer, uncovered for about 15-20 minutes until the sauce has thickened slightly.
Stir in the coriander and season to taste.
Meanwhile, preheat the oven to 200°C.
To make the dumplings; Place polenta flour and butter in the Thermomix bowl and mix 5 sec/speed 6 until breadcrumbs. Add rest of ingredients and mix on 5 sec/Reverse/speed 4.
Spoon the bean mixture into a 2 litre pie dish and drop level tablespoons of corn mixture on top of the chilli. Bake uncovered, for about 20 minutes or until the cornbread dumplings are golden brown.