Wash toovar dal. Wash and cut drumsticks into two-inch lengths. Peel, wash and chop garlic. Peel, wash and slice onion finely. Wash and chop tomatoes. Place dal with turmeric powder and salt in a pan with one and a half cups of water.
Cook half covered for ten minutes, then add drumsticks and chopped garlic. Cover and cook for ten more minutes or till the dal is soft. Meanwhile infuse tamarind in four tablespoons of hot water for five minutes. Strain the pulp and leave it aside.
Heat ghee in a pan and fry onion till pink. Add mustard seeds and when they crackle add it to the dal mixture. Add tamarind juice, whole red chillies, cumin powder and tomatoes to the dal mixture and simmer for another fifteen minutes.
The consistency should be fairly thin.