I find that the easiest and tastiest Sambal Ikan is made with canned tuna fish. Sambal made with eel, however, is also delicious; cut the eel up very small and wash it in vinegar. In Indonesia we make this sambal with ikan teri or ikan bilis (tiny dried anchovies). Pound the garlic, shallots, kemiri and cabe rawit into a paste. Fry this paste in vegetable oil in a wok for about half a minute. Put in the tuna fish, eel or teri; stir-fry for 1 minute and add the tamarind water, or tomato puree, sugar and salt. Stir in the santen, and go on simmering until the mixture becomes thick. This sambal can be served hot or cold.