This cuisine is characterised by the use of a common base for all the sauces to which spices are added when individual dishes are prepared. The standard "feedstock" is usually a sautéed mixture of onion, garlic and fresh ginger, to which various spices are added, depending on the recipe, but which may include: cloves, cinnamon, cardamom, chilies, peppercorns, cumin and mustard seeds. Ground coriander seed is widely used as a thickening agent, and turmeric is added for colour and its digestive qualities. Fresh or canned tomatoes and bell peppers are a common addition.