Preheat the broiler to high. In a small saucepan, combine mirin, lemon juice, miso paste, and 1 teaspoon ginger. Boil for five minutes, then remove from heat and allow to cool.
Place cod in a shallow baking dish and cover with marinade. Cover and refrigerate for 30 minutes.
In a medium pan, warm 1 tablespoon avocado oil and sauté red peppers over medium-high heat for 10 minutes, until caramelized and slightly brown on edges.
Heat 1 tablespoon sesame oil in the same skillet over medium-low heat. Add garlic and 2 teaspoons ginger and cook until softened, about three minutes. Add cabbage and soy sauce and cook until cabbage has wilted, about three more minutes.
Place fish on a foil-lined baking sheet and broil for five to six minutes, until glaze bubbles and edges turn brown. Remove from heat and allow to cool.
Layer fish on top of cooked rice and vegetables. Garnish with cilantro, green onions, and sesame seeds.