Put the garlic and the olive oil into a heavy saucepan and cook gently for a few minutes. Just before the garlic turns brown, add the tomatoes. Simmer for 30 minutes, stirring occasionally, until the tomatoes become concentrated. Season with salt and pepper, then add 600 ml (1 pint) water and bring to the boil.
Cut most of the crust off the bread and break or cut into large chunks. Put