Toast the coriander seeds, cinnamon stick, dried chili, mustard seeds, cloves, cardamom and allspice until the mustard seeds start to pop. In order to do this properly, it is critical to preheat the cast iron pan to 148ºC (300ºF) before putting spices in the pan. Move the pan in a circular motion to allow spice seeds to roll and avoid burning. Manually turn larger flat sided pieces of serrano chili and cinnamon stick. Transfer spices in a small bowl and let cool for 2-3 minutes.