1To make shredded fresh coconut, rinse coconut thoroughly to remove any dust or dirt from shell; pat dry. Pierce eyes with ice pick or sturdy skewer. Drain liquid into container. (The liquid is delicious to drink and can be stored in the refrigerator in a covered container for up to 24 hours.)
2Tap coconut firmly all over with hammer or heavy meat mallet. It usually splits open lengthwise. Work blade of blunt or round-ended knife between white meat and hard shell. Push knife into shell away from you and, with a twist of the wrist, the meat should pop out. Peel thin, dark brown skin from white coconut meat, using paring knife or vegetable peeler. Shred the coconut meat in a food processor or on large holes of four-sided grater. One medium coconut yields 2 to 3 cups shredded coconut; use 1 cup for this recipe.
3To make chutney, in blender, place 1 cup coconut, the water, cilantro, tamarind pulp, salt and chiles. Cover and blend on medium speed until smooth. Transfer to small bowl; set aside. (Chutney will thicken as it stands; if it becomes too thick, stir in additional water until it reaches desired consistency.)
4In 6-inch skillet, heat oil and mustard seed over medium-high heat. Once seed begins to pop, cover skillet and wait until popping stops. Add lentils; stir-fry about 30 seconds or until lentils are golden brown. Pour hot oil mixture over chutney; mix well. Cover tightly; store in refrigerator up to 1 week.