Step 1

Place beans in a large pot, cover with cold water and leave to soak overnight. Drain and cover with fresh water (do not add salt). Bring to a boil and cook uncovered until tender (about 1-1½ hours, depending on age and dryness of beans).

Step 2

While beans are cooking, remove stems from dried smoked chillies and discard. Cover chillies with boiling water and soak 30 minutes until tender.

Step 3

Meanwhile, toast cumin and coriander seeds in a dry pan over medium-high heat, shaking occasionally, until fragrant and starting to pop (about 1 minute). Crush with a mortar and pestle.

Step 4

Heat oil in a large pan and cook onions and garlic over a low heat until softened but not browned (about 10 minutes). Add crushed seeds, oregano, fresh chilli, tomatoes, sugar, salt and pepper and bring to a boil.

Step 5

Lift the smoked chillies out of their soaking liquid, reserving the liquid. Chop finely and add to the tomato sauce with the soaking liquid and the drained cooked beans. Bring to a boil and simmer uncovered, stirring occasionally to prevent catching, until thick (about 45 minutes). Alternatively, bake for about 1½ hours in an oven preheated to 180C.

Step 6

To serve, adjust seasonings to taste then spoon into a deep serving dish and top with coriander.