Makes about 300 gms
Heat oil in a kadai or wok and roast the red chillies on low-medium heat. Use two ladles and roast by lifting the chillies from the sides until they are very hot to the touch. Let the chillies not burn or the chilli fumes will take over the kitchen. Spread on a plate and keep aside.
Add Ghee to the kadai followed by black peppercorns and roast on medium heat until the spluttering frequency reduces but does not stop. Remove on to the plate.
Use a mixture of mild and hot varieties of red chilli like Guntur(hot) and Byadagi (mild). Read more notes on this in Bisi Bele Bath recipe
AVOID dry roasting all ingredients together as it results in uneven roasting or burning of ingredients. If you wish to make a smaller batch, a 4:1 ratio should work well between coriander seeds and cumin, fenugreek and black pepper. Adjust proportion for the other ingredients accordingly.
Avoid dry roasting red chillies or they'll emanate pungent, choking fumes. If you feel the spice mix turned out to be short of red chillies or doesn't taste hot enough, you can always adjust by roasting some extra chillies, grind to a fine powder and grind once again together with the Podi to get it all mixed well.
If you happen to make Rasam only once in a while, then consider storing it in the freezer. That way, the spice mix will retain all of its flavor without tasting like just wood husk.
SSP brand hing is available in Bangalore - Mysore areas as far as I know. LG brand is available even in the US.