In a small bowl, mix the garlic, lemon juice, honey, butter, cayenne pepper and salt together. Whisk to combine well.
Rinse the salmon with cold water and pat dry with paper towels. Transfer the salmon to a big sheet of aluminum foil and drizzle the garlic lemon butter mixture on the salmon. Coat well. Top with parsley. Wrap the salmon up tightly and bake for 20 minutes, or until the salmon is cooked through.
Unwrap the foil, garnish with sliced lemon and serve immediately.