A classic of the Mangaloreans in southern India, this recipe traditionally uses small green mangoes. Try it as a side dish with Cornish hens or roast turkey. Combine sesame seeds, fenugreek and coconut in an 8 to 10-inch skillet. Dry-roast over medium heat, shaking pan often until seeds become aromatic and darken 1 or 2 shades, about 6 to 8 minutes. Place in a spice or coffee grinder and reduce to a powder. Combine pineapple chunks and juice with turmeric, brown sugar, salt, cayenne and ground spice mixture in a 1-quart saucepan. Cover, and cook over medium heat until thick, about 8 to 10 minutes. Heat oil in a small frying pan over medium-high heat. Add mustard seeds; when seeds pop (takes about 1 minute) stir in curry leaves or cilantro. Remove immediately and pour over pineapple curry. Serve hot. PER SERVING (4 servings): 70 calories, 1 g protein, 10 g carbohydrate, 3 g fat (1 g saturated), 0 mg cholesterol, 135 mg sodium, 1 g fiber. Laxmi Hiremath writing in the San Francisco Chronicle, 6/42/92.