The coriander seeds and the pepper corn are to be taken in a ratio of 5:1, i.e. is for 5 cups of coriander seeds you take 1 cup of pepper corns.
Fry each ingredient separately on medium to high heat. Each ingredient should be fried till dark brown to blackish color, or till the spices let go a flavor aroma.
Mix all fried ingredients and grind them into a fine powder.