STOVE TOP: Using a large pot, sautee the chopped onions, mushrooms, celery, carrots, and ginger for 5 minutes. Add 2 Tbsp of water if needed to keep veggies from sticking. Add the chopped turnips and water bring to a boil, reduce to a gentle boil and cook for 15 minutes. Check to see if the turnips are fork tender. If not, cook an additional 5 minutes. Add all remaining ingredients EXCEPT for miso paste mixture and green onions. Return to a medium boil and cook for an additional 5-7 minutes, stirring frequently. Remove from heat. Add the miso and water mixture. Mix well. Serve garnished with green onions.