Start preparation the day before you plan to serve this dish. Rinse the beans in a sieve and place in a bowl with enough cold water to amply cover them; add 1/2 tsp bicarbonate of soda.

Leave the beans to soak overnight or for more than 12 hours, then drain, place in a saucepan with enough water to cover them completely and bring slowly to the boil over a moderate heat. Cover, leaving a gap so that the steam can escape. Simmer very gently for about 1 1/2 hours or until the beans are very tender. Remove the scum from the surface of the water at intervals. Add a large pinch of salt when the beans are nearly done.

While the beans are cooking, make the sauce: heat the olive oil in a saucepan over a moderately low heat and add the whole garlic clove, partially crushed with a flat of a heavy knife blade. After about 1 minute, when the garlic is pale golden brown, add the chopped tomatoes. Turn up the heat, add the seeded, crumbled chilli pepper and a pinch of oregano; cook briskly, stirring, for 2 - 3 minutes. Set aside.

When the beans are done, put them with their cooking liquid through the vegetable mill with a fine-gauge disc fitted. Ladle the resulting puree into individual heated bowls, spoon some of the tomato mixture into the centre of each bowl, drizzle a little olive oil on to each serving and sprinkle with a generous amount of freshly ground black pepper.

Garnish with the basil sprigs and serve with garlic bread.