"As a vegetarian, I'm always looking for interesting ways to combine vegetables. The flavorful gravy in this dish comes from the mushroom-soy sauce-miso combination. Eat alone or as a side dish. Enjoy!"
Melt butter in a skillet over medium heat. Cook and stir onion in butter for 1 minute. Stir mushroom into onion; continue cooking and stirring until mushroom softens, about 3 minutes more. Pour soy sauce over mushroom mixture; cook for 1 minute and remove from heat.
Pour hot water into a casserole dish. Stir bouillon in the hot water to dissolve. Mix potato, kohlrabi, and carrot in the bouillon mixture. Add mushroom mixture to potato mixture; stir. Top with bay leaf, parsley, seasoned salt, and black pepper. Stir again to evenly distribute seasoning.
Divide miso into 4 portions; place atop vegetable mixture.
Bake in the preheated oven for 20 minutes, stir, and continue cooking until vegetables are tender, about 15 minutes more.