serves 4–6; adapted from Julie Sahni, Classic Indian Cooking
Rinse lentils with water until it runs clear, then let them soak in water while you gather the other ingredients.
Heat ghee/oil in large saucepan over medium heat. Add onion and cook until softened, about 5 minutes. Add garlic & turmeric and cook another minute. Add tomatoes and cook for a couple minutes more. Add drained lentils, 4 cups water, salt, bring to boil then reduce heat to maintain a low simmer for 30 minutes.
Heat ghee/oil over medium heat in small frying pan. Add mustard seeds and cook for a couple minutes, the seeds will begin popping. Add ginger, chile flakes, and cumin and cook for a couple minutes more. Stir entire mixture into cooked lentils.