From the Smitten Kitchen website, which credits:
Madhur Jaffrey, Indian Cooking
Serves 4 to 6
200 grams (1 1/4 cups) red split lentils (masoor dal), picked over, washed and drained
1.2 liters (5 cups) water
1/2 teaspoon ground turmeric
5 tablespoons vegetable oil
1 teaspoon cumin seeds
2 to 4 cloves garlic, peeled and finely chopped
1 medium onion, peeled and cut into fine slices
225 grams (1/2 pound) cored and finely shredded cabbage
1 to 2 fresh, hot green chilies, finely sliced
1 1/2 teaspoons salt
1 medium tomato, peeled (ahem, Deb did not peel her tomato) and finely chopped
1/2 teaspoon peeled, finely grated fresh ginger
Put the lentils and water into a heavy pot and bring to a boil. Remove any scum that collects at the top. Add the turmeric and stir to mix. Cover, leaving the lid very slightly ajar, turn heat down to low, and simmer gently for 1 1/4 hours. Stir a few times during the last 30 minutes.
When the lentils cook, heat the oil in a 20 to 23 centimeter (8 to 9 inch) frying pan over medium heat. When hot, put in the cumin seeds. Let them sizzle for 3 to 4 seconds. Now put in the garlic. As soon as the garlic pieces begin to brown, put in the onion, cabbage and green chilies. Stir and fry the cabbage mixture for about 10 minutes or until it begins to brown and turn slightly crisp. Stir in 1/4 teaspoon of the salt. Turn off the heat under the frying pan.
When the lentils have cooked for 1 1/4 hours, add the remaining 1 1/4 teaspoon salt, the tomato and ginger to the pot. Stir to mix. Cover and cook another 10 minutes. Add the cabbage mixture and any remaining oil in the frying pan. Stir to mix and bring to a simmer.
Simmer uncovered for 2 to 3 minutes or until the cabbage is heated through.