In a small bowl, mix together the garlic, soy sauce, honey, and butter. Whisk until well combined.
Rinse the salmon under cold water and pat it dry with paper towels. Transfer the salmon to a large sheet of aluminum foil and drizzle the garlic soy butter mixture over it, coating well. Top with parsley, then wrap the salmon tightly in the foil. Bake for 20 minutes, or until the salmon is cooked through.
Unwrap the foil, squeeze some lemon juice over the salmon, garnish with lemon slices, and serve immediately.