The addition of spice-scented oils, or tarkas, made by popping mustard seeds and curry leaves and other ingredients in hot coconut or vegetable oil, at the end of cooking is a common Indian culinary technique and is known as tempering. A combination of mustard seeds, black gram, dried red chillies, and curry leaves fried in ghee or coconut or vegetable oil is one example of numerous oil flavourings used for sambar. Some variations include additional ingredients such as cumin seeds, shallots, fenugreek seeds and asafoetida powder.