Put the beans into a pan, cover with water and bring to the boil, boil for 10 minutes, then lower the heat and simmer for about 45 minutes, until tender.

Meanwhile, make the pastry: sift the flour and a pinch of salt into a bowl and rub in the fat until the mixture resembles fine breadcrumbs and add just enough water to make a firm dough.

Roll out on a lightly floured surface and use to line a 20 cm (8 inch) deep flan dish. Chill for 10 minutes.

Prick the base of the pastry case and bake blind with foil and beans in a 200°C (400°F) mark 6 oven for about 10 minutes or until just set. Remove the foil and beans.

Beat the eggs, cream, milk and Parmesan together. ¢â‚¬Â¢ Season and pour into the flan case. Bake at 180°C (350°F) mark 4 for about 25 minutes, until lightly set.

Meanwhile, melt the butter in a pan and slowly fry the onion. Stir in the tomatoes, oregano, sugar and seasoning to taste. Simmer in the open pan for about 15 minutes, until the liquid has evaporated.

Drain the beans and add to the hot tomato mixture. Reheat and spoon over the flan filling. Serve hot.