Let cool, then finely grind in spice mill. (bonappetit.com)
Using spice mill or mortar and pestle, coarsely grind fennel seeds and red pepper flakes. (bonappetit.com)
Use an electric spice mill and be sure to wear a painter's mask to protect your nose and throat from the pungent cloud of powder that you will create. (fieryfoodscentral.com)