Steps
1. Preheat grill to medium-high heat.
2. Season the mackerel fillet with salt and pepper.
3. Place lemon slices on the fillet.
4. In a small bowl, mix melted butter, minced garlic, and chopped parsley.
5. Grill the mackerel for about 5-6 minutes per side, basting with the lemon herb butter.
6. Serve hot and enjoy!