Preheat the oven to 400°F (207°C). Place a large sheet of aluminum foil on a baking sheet (this makes it easier to transfer and catch any juices).
In a small bowl, whisk together 3 cloves minced garlic, 1 1/2 tablespoons lemon juice, 1 1/2 tablespoons honey, 2 tablespoons melted butter, 3 dashes cayenne pepper, and 1/4 teaspoon salt until well combined. (If your butter is not already melted, melt it and let it cool slightly before adding.)
Rinse the 1 lb. (450 g) salmon fillet under cold water and pat it dry thoroughly with paper towels.
Place the salmon in the center of the foil on the baking sheet. Drizzle or spoon the garlic-lemon butter mixture evenly over the top and sides of the salmon so it is well coated.
Sprinkle 1 tablespoon chopped parsley over the coated salmon.
Fold the foil up and seal it tightly to form a packet, leaving no large openings for steam to escape. Place the foil packet on the baking sheet.
Bake for 20 minutes, or until the salmon is cooked through (opaque and flakes easily with a fork).
Carefully open the foil away from your face to avoid steam, garnish with sliced lemon, and serve immediately.