Prick sausages with a fork. Peel onions and garlic. Onions in columns, garlic in fine slices cut. Wash the rosemary and shake dry. Boil up onions, garlic, bay leaf, rosemary and sherry in a pot.
Add red wine and stock. Season with salt and pepper. Place the sausages in the stock and simmer for about 20 minutes. Arrange in a bowl.