Pat your cod fillets completely dry using paper towels, removing all surface moisture. This step ensures proper browning and helps the spice rub adhere evenly to each fillet before grilling begins.

In a small bowl, whisk together smoked paprika, garlic powder, onion powder, black pepper, sea salt, dried thyme, and cayenne pepper until fully combined. Add fresh lemon juice and Dijon mustard to create a thick paste that coats every side of the fish.

Brush olive oil lightly over your grill grates, then preheat to medium-high heat for approximately 5 minutes until the surface is smoking hot. This prevents sticking and creates beautiful char marks that add visual appeal.

Generously coat each flaky smoky grilled cod recipe fillet with the spice paste, ensuring all sides receive equal coverage. Place fillets skin-side up on the preheated grill, then cook for 6 minutes without moving to develop a golden crust.

Carefully flip the fillets using a thin metal spatula, placing a lemon slice directly on top of each fillet. Cook for an additional 5-6 minutes until the fish flakes easily with a fork and reaches an internal temperature of 145°F.

Transfer grilled cod to a serving platter and immediately top each fillet with a small pat of butter and fresh chopped parsley. The residual heat will melt the butter into a silky sauce that enhances the smoky spice blend beautifully.