Soak the black beans in 2 litres of cold water overnight.
Heat half of the oil in a large lidded frying pan over medium heat.
Season all pork ribs with salt and pepper and fry for 5 minutes per side until browned.
Add onion and garlic and fry for 3 minutes until softened.
Add 250ml water, simmer covered for 20 minutes, then transfer to a large casserole.
Fry bacon, pork belly, and sausage in batches until browned and add to the casserole.
Add beans with their soaking liquid, bring to a boil, and simmer half-covered for 2.5 hours.
Season with salt, pepper, and chilli flakes before serving.