Lightly roast each spice (except amchur and turmeric powder) in a small pan until they are hot and fragrant, about a minute. Stir frequently and make sure not to burn by roasting too long. The goal is to make them a bit toasty so they are easy to grind.
Cool spices and then grind fine in a coffee or spice grinder. Add amchur powder and turmeric powder and mix well. Store in an airtight container away from direct sunlight.
If you do not have amchur powder, you can simply skip it and instead squeeze the fresh lemon juice into the chana masala once it is done cooking.
Ground cumin can be used instead of whole cumin
This recipe makes 4 oz of chana masala spice blend