Heat the oil in a pan and add the cumin and mustard seeds. When they stop spluttering, add the garlic, dry red chillies, asafetida, pepper and curry leaves. Fry until the garlic turns pale golden in color. Add the tomato and water. Taste and add salt as needed. Simmer and boil for 10 minutes. Add the lime/lemon juice and mix well. Turn off the fire. Add the coriander leaves and serve piping hot in cups or in a bowl with rice.