Dry roast each of the different whole spice types individually until they become fragrant. (*Roast Curry Leaves to dry out and become lightly brown.) Transfer to a bowl and let cool.
Grind the spices together into a fine powder in a spice grinder (or mortar and pestle if you don't have a grinder). Stir in the turmeric, cayenne, ginger, and chilli powders to combine.