Wash the cranberries in cold water, put them in an earthenware casserole with 1 pint of water, bring to the boil and simmer for 20 minutes, crushing the berries to extract the juice. Remove from the fire and stir in the sugar. Replace on a slow fire and simmer 10 to 15 minutes longer. Put the berries in a basin, but do not strain. When cold, put in a pie dish lined with crust which has already been slightly baked, decorate with strips of pastry, and bake till the strips of pastry are a delicate golden colour.