Sambar powder is easily available in most Indian stores. However, we prefer our own spice mix. This is what goes into our Sambar powder.
SAMBAR POWDER RECIPE
1 cup dhaniya(coriander seeds)
2 cups dried red chillies
1/4 cup kadale paruppu (Channa dal)
1/4 cup Uzhutham paruppu (Urad dal)
1/4 cup venthyam (methi seeds)
1.Dry roast all the ingredients separately until they give a nice aroma. (The dals should just about start turning to a pale brown)
2.Let cool and dry grind everything together and store in an air tight container.
3.Stores well for 4-5 months.