Preheat a large skillet over medium-low heat. If using an oven, preheat it between 330 and 350 degrees F.
Spread the coriander, cumin seeds, fennel seeds and black pepper in an even layer in your skillet or baking sheet.
Cook the seasonings and give them a toss every 30 seconds if using and pan. They will start smelling fragrant in around 3 to 5 minutes and will have lightly darkened. At this point, remove them from the heat and let them cool to room temperature.
If cooking in the oven you only need to toss them once at around the 3-minute mark. After tossing cook them for another 2 to 3 minutes. Remove them from the oven and let cool to room temperature.
After the seasonings have cooled, place them along with the remaining ingredients into a spice grinder or a coffee grinder. Grind them until smooth
Place the freshly ground seasonings in an air-tight container if not using right away. If stored properly, they will keep for a few months before they start to lose their quality.