To make the glaze: In a large bowl combine the miso paste, tamari or soy sauce, sugar, sesame oil, shichimi togarashi and minced ginger and garlic.
Preheat grill to medium.
Brush the portobello mushrooms and baby bok choy with the glaze. Place them face down on the hot grill. Grill over medium heat until you hear good sizzle and see nice grill marks. Mushrooms start to release water.
Using the tongs, flip the veggies and brush the top part with the glaze. Let the other side cook for few more minutes.
Turn off the grill. Remove the veggies for the grill. Brush the glaze one last time before serving. Serve warm.