Jean-Georges calls this “cod spice” because he uses it on cod all the time, but it’s great on any white-fleshed fish that you’re planning to roast, grill, or even steam.
Combine the spices in a small dry skillet and turn the heat to medium. Toast, shaking the skillet periodically, until the spices are fragrant, just a minute or two.
Grind in a mortar and pestle or a spice or coffee grinder. Store, covered, for up to several months.