In a pan over medium heat, add the kashmiri chilies, coriander seeds, cumin seeds, cinnamon (or cassia bark), cardamom pods, fenugreek seeds, and black peppercorns. Stir often until fragrant (30 seconds to 1 minutes).
Transfer the spices from the pan to a large mortar or spice grinder. Crush the spices into nearly a powder, then add the turmeric and cayenne pepper powder. Continue crushing until all the ingredients are powdered.
Use immediately, or transfer to a sealable airtight container and store for future use.