
Preheat the oven to 200C/400F. Cut the cabbage into quarters.
Mix 2 tbsp of the softened butter with the miso paste and brush on the cabbage quarters all over, including the base. Place the cabbage wedges on a baking sheet and roast in the preheated oven for 30-35 minutes until charred on the outside and slightly crispy.
While the cabbage is roasting, melt the remaining tablespoon of butter in a pan, then add the breadcrumbs and garlic powder. Toast while stirring continuously until golden, then remove from the pan immediately.
Sprinkle the cabbage with the breadcrumbs before serving. Optionally, add chopped parsley.