Wash lentils in several changes of cold water. In a medium pot, cover with the water and add the whole dried chiles, turmeric, and salt. Bring to a boil, reduce heat, and simmer, stirring often, until very tender. This will take about 30 minutes for red lintels, 45 minutes for peas, or an hour or more for mung beans. It may be necessary to add more water to prevent sticking,but only 1/2 cup at a time, because the final consistancy should be fairly thick. When the lentils are almost cooked, heat the oil in a small pan, add the cumin seeds, and cook for 10 or 15 seconds. Stir in the onions and ginger and cook until the onions begin to brown, about 5 or 10 minutes. When the lentils are tender, remove and discard the hot peppers. Stir in the onion mixture, lemon juice, garam masala, and salt to taste. Serve, passing additional garam masala to sprinkle on top, if desired.
VARIATIONS Spinach Dal: Add 4 cups of chopped, fresh spinach to the onions after they have sauteed for about 5 minutes and then cook for 5 minutes more. Tomato Dal: Add 1 cup chopped tomatos to the onions after they have sauteed for about 5 minutes and then cook for about 5 minutes more. Spinach- Tomato Dal: Add both spinach and tomatoes.