How to Make It
Combine all ingredients in a small bowl and stir until evenly blended. If using fresh lemon zest, add it last and toss quickly with a fork to distribute it without clumping.
The rub should smell bright and citrusy with a sharp pepper bite. If the lemon scent is faint, you need more zest. Let it rest for about 15 minutes before using. The citrus oils need a few minutes to distribute through the pepper and spices for a more even flavor.
How to Use It
For fish fillets: Pat the fish completely dry with paper towels. Apply about 1 teaspoon of rub per fillet, pressing gently into the flesh side. Let rest 10 to 15 minutes, then grill skin-side down over medium-high heat or pan-sear in a hot skillet with a little olive oil.
For shrimp: Toss peeled, deveined shrimp with a drizzle of olive oil and about 1 tablespoon of rub per pound. Thread onto skewers or use a grill basket. Cook over high heat for 2 to 3 minutes per side until pink and slightly charred.
For scallops: Pat dry scallops are critical. Any moisture will prevent a sear. Dust lightly with the rub on both sides. Sear in a ripping hot cast iron skillet with a neutral oil for 90 seconds per side.
For salmon: This rub is great on salmon. Apply a generous coat to the flesh side of skin-on fillets. Grill skin-side down at 400 degrees for 10 to 12 minutes without flipping.
Working with Seafood
The biggest mistake people make with seafood rubs is using too much. Fish and shellfish have delicate flavor that you want to complement, not bury. Think of this rub as seasoning, not a coating. A light dusting goes much further on a piece of halibut than a heavy layer does on a pork shoulder.
Always start with dry seafood. Moisture is the enemy of a good sear, and wet fish will steam instead of crisping. Keep paper towels handy and pat everything dry right before the rub goes on.