Combine coriander, red chilies, cumin, black peppercorns, and carom in a small skillet. Gently cook, stirring often, on medium low heat until lightly toasted and fragrant, about 5 to 7 minutes. Remove from heat and cool completely.
Combine the remaining ingredients in a separate bowl and mix well.
Once the roasted spices have cooled, grind to a fine powder. Whisk together both sets of spices and store in an airtight container at room temperature.