Steps
1. In a small bowl, mix together miso paste, soy sauce, honey, garlic, and ginger to create the glaze.
2. Pat the mackerel fillet dry and brush the glaze on both sides.
3. Preheat a grill or grill pan over medium-high heat.
4. Grill the mackerel for 3-4 minutes per side, or until cooked through and caramelized.
5. Remove from the grill and garnish with sesame seeds and green onions before serving.