Stir the polenta into a large pan of salted boiling water. Cook over a moderate heat, stirring continually for 5 minutes, then frequently for a further 35 minutes, until the polenta becomes very thick.

Meanwhile, cut the ham slices into strips, and finely chop the onion and garlic. Heat the olive oil in a frying pan and cook the onion, garlic, bay leaf, chopped parsley and basil over a gentle heat for 5 minutes. Add the tomatoes, breaking them up with a spoon. Increase the heat and cook for 15 minutes, until the mixture is soft.

Remove the bay leaf and blend the mixture in a liquidiser until smooth. Add the sugar and season to taste. Return to the pan and simmer for 10 minutes, until quite thick. Taste and adjust the seasoning.

Turn the cooked polenta into a buttered baking tray and leave to cool for 30 minutes, until firm, then turn out and cut into slices. Butter a gratin or baking dish, and spread a thin layer of tomato sauce over the bottom. Place the polenta slices in the dish in a single layer.

Mix the ham strips with a small amount of the tomato sauce and spread over the polenta. Slice the Fontina and place the slices over the meat, then spread over the remaining sauce.

Break the goat or blue cheese into small pieces and sprinkle over the top, adding a little more black pepper. Bake, uncovered, for 30 minutes, then remove and sprinkle with the fresh mixed herbs. Serve immediately.