Provençal Bacon Casserole

• 3½-4 lb. joint prime collar bacon, boned and rolled
• ½ pint white wine
• Water to cover

Soak joint overnight in cold water. Place in a saucepan with wine and cold water and simmer for half the cooking time, allowing 25 minutes per pound and 25 minutes over. Drain joint and remove the skin. Place on a large piece of foil in an ovenproof dish. Blanch onions for 10 minutes then drain. Melt butter in a pan and sauté onions until lightly golden. Add tomatoes and oregano and simmer gent