Steps
1. Preheat the grill to medium-high heat.
2. In a small bowl, mix together minced garlic, parsley, thyme, salt, pepper, and olive oil.
3. Place the mackerel fillet on a piece of foil. Squeeze half of the lemon over the fillet.
4. Spread the herb mixture evenly over the mackerel.
5. Top with lemon slices.
6. Wrap the foil around the mackerel to create a packet.
7. Grill the packet for 10-12 minutes, or until the mackerel is cooked through.
8. Serve hot and enjoy!