Like other members of the brassicas family, rutabagas are high in antioxidant and anti-cancer compounds. Just 1 cup of this nutty and sweet root vegetable also will give your immune system a boost, with 53 percent of your recommended daily allowance of vitamin C. Rich in beta-carotene, rutabagas also are a good source of potassium, manganese, fiber, thiamin, vitamin B6, calcium, magnesium and phosphorus.
Peel the skin off rutabaga with a carrot peeler and chop into thin rectangular pieces (1/8 inch thick) to accelerate cooking time. Bring saucepan to medium heat, then add olive oil. Sauté 3/4 of green onions (save some for garnish) until soft and glistening. Add rutabaga and sauté until brown and soft. Combine kale with rutabaga and add cooking sake. After vegetables absorb sake, reduce heat to low and remove from heat. Serve warm, with a splash of tamari and garnish with green onions.