To make the tomato sauce: Heat the olive oil in a heavy pan, add the onion and cook for 3 minutes, stir in the garlic and continue to cook until the onion is soft. Add the tomatoes, sugar and salt to taste. Cook over a moderate heat, stirring from time to time, for 20 minutes. Pass through a fine sieve or vegetable mill into a clean saucepan.

Using a sharp knife or a mandolin, cut the aubergine lengthwise into 5mm(¼inch) thick slices. Sprinkle the slices both sides with salt and leave to drain for 30 minutes. Rinse the aubergine slices and dry with kitchen paper. Brush the slices with the olive oil and place one layer on a grill rack. Cook under a hot grill for 3-4 minutes on each side or until golden brown. Repeat until all the slices are cooked. Leave to cool.

Mix together the mozzarella, goats cheese and basil. Spread a tablespoon of the cheese mixture lengthwise down the middle of each slice of aubergine and roll them up. Arrange the rolls, seam side down in an oiled shallow baking dish. Grill for 3 minutes or until the cheese has just melted and is bubbling.

Reheat the sauce and allow to boil until is has thickened slightly.

To serve: arrange the aubergine rolls on 4 serving plates, pour a ribbon of sauce over and garnish with the sprigs of basil.