In a small sauté pan, add the cardamom pods, cumin seeds, star anise and cinnamon sticks over medium heat. Toast, stirring constantly until fragrant, 2 to 3 minutes. Transfer the mixture to a spice grinder to cool.
To the pan, add the nigella and mustard seeds, and toast until fragrant, 1 to 2 minutes. Transfer the toasted seeds and the Persian limes to the spice grinder. Grind into a coarse powder. Transfer to a small bowl and mix in the chile flakes and mace to incorporate.
Use immediately or store in an airtight container in a cool, dry place for up to 1 year.