Toast the whole spices: Put the black peppercorns, coriander seed, and dill seed in a dry skillet over medium heat. Cook, stirring frequently, until fragrant and just darkening at the edges, 2â3 minutes; do not scorch.
Cool and crack: Transfer the toasted spices to a plate to cool for 5 minutes. Coarsely crush them with a mortar and pestle or pulse in a spice grinder in short bursts until chunky, not finely ground.
Mix the blend: In a bowl, combine the cracked spices with the garlic granules, onion flakes, crushed red pepper flakes, sweet paprika, and kosher salt. Stir until evenly mixed.
Finish and store: Let the seasoning cool completely, then transfer to an airtight jar. For steaks, use about 1â2 tsp per 1 lb (450 g), pressing it onto the meat and letting it sit 20â30 minutes before grilling or broiling. Store in a cool, dark place for up to 6 months.