Fry the onions in the oil for 5 mins until they become soft and start to colour.
Add the chorizo and fry for a few mins more. Stir in the peppers, then pour in the tomatoes, followed by a can of water, the stock cubes, chilli and oregano.
Arrange the chicken thighs on top of the sauce, pushing them under the liquid. Bring to a simmer, cover, then cook in the oven for 40 mins.
Add the beans, stir, then cook for 20 mins more. You can make this up to 2 days ahead and keep chilled.
To serve, reheat on the top of the stove or in the oven at 190C/fan 170C/gas 5 for 1 hr 10 mins until piping hot. Stir in most of the coriander, toss the rest with the avocado, lime and a little salt, then pile this on top.
Serve with Garlic & oregano bread (below) and a bag of green salad tossed with olives, cherry tomatoes and finely sliced red onion.