First make the tomato sauce. Heat the oil in a shallow casserole and saute the onion and garlic until the onion has wilted.
Add the tomatoes, tomato puree, water, parsley, salt, pepper, sugar and wine. Cover and simmer for 15 minutes then set aside.
Clean the squid well leaving the bodies in one piece. Finely chop and reserve the tentacles.
Heat 2 tbsps oil in a pan and saute the onion and garlic until wilted. Add the chopped tentacles and the ham if using. Cook for 2 minutes then remove from the heat.
Add the paprika, parsley, salt, pepper, wine and breadcrumbs. Stuff the squid, dust with flour then fry briefly in the remaining oil, turning once.
Put into the tomato sauce then cover and cook over a gentle heat for an hour. Serve with a salad and some white wine if you do.