They use asafoetida, fenugreek, curry leaves, mustard, and urad dal.
en.wikipedia.org The main ingredients are a mixture of sauteed herbs, consisting mainly of parsley, leeks or green onions, coriander, seasoned with the key spice of shambalileh (dried fenugreek) leaves.
en.wikipedia.org Commonly used spices include mustard, "methi" or the seeds of fenugreek, chilli powder, salt, asafoetida and turmeric.
en.wikipedia.org The dried fenugreek leaves have a bitter taste and strong smell, hence careful quantities must be used.
en.wikipedia.org