Dry-Toasting Method. Cumin and Coriander toast at approximately the same rate, although the cumin seed will burn slightly before the coriander so watch those seeds for browning.
Before you begin have a hot pad and scratch piece of paper to use as a funnel at the ready.
Place the desired amount of seeds in the bottom of a cast iron pan. Turn heat to medium high and begin warming then toasting the spices. Keep seeds moving in the pan as they begin to heat. Once they begin smoking a bit their aromatic oils will be released, and then it is time to IMMEDIATELY REMOVE SEEDS FROM THE PAN TO PREVENT BURNING ( USING THE HOT PAD). Quickly pour the seeds out of the pan onto scratch paper.
Once they have cooled a moment, place in spice grinder and grind to desired consistency.

Once they have cooled a moment, place in spice grinder and grind to desired consistency.
