Slice off about 2 1/2 cm (1 in) from the wider end of each pepper. Carefully remove and discard the pith and seeds. Set aside.

Remove and discard the stems from the sliced tops and chop the flesh into small dice. Set aside.

Heat half the oil in a large frying-pan. Add the onion, garlic and pepper dice and fry until the onion is soft.

Stir in the tomatoes and can juice, tomato puree (paste), herbs, salt and pepper. Cover and cook, stirring occasionally, for 25 minutes, or until the mixture has thickened. Stir in the remaining ingredients, except the cheese, and cook the mixture for 5 minutes. Preheat the oven to warm 170°C (Gas Mark 3, 325°F).

Remove from the heat and spoon the sauce into the peppers, filling them to within about 1 cm (1/2 in) of the top.

Brush a baking pan with about 1 tablespoon of the remaining oil. Arrange the peppers in the pan and put the pan into the oven. Bake for 45 minutes, basting occasionally with the remaining oil.

After 45 minutes, sprinkle the tops of the peppers with the grated cheese and bake for a further 15 minutes, or until the cheese is brown and bubbly. Remove from the oven and serve at once.