Prep the cashews. Pour hot water over the cashews and let them soak for at least 10 minutes to soften.
Prep the turnip. While the cashews are soaking, chop the turnip or kohlrabi into bite-sized pieces. Boil the turnip pieces in a pot of salted water for about 20 minutes or until tender. Once the pieces have softened, drain the water and mash them roughly – a few chunks are ok.
Make the cheeze sauce. Break up the tofu into chunks and add it to a blender or food processor, along with the nutritional yeast, garlic, olive oil, miso, vinegar, vegetable broth, and cornstarch. Drain the cashews and add the softened cashews to the blender as well. Blend it all together until it is very smooth, occasionally scraping down the sides of the blender. Add salt/pepper to taste.
Assemble and bake. Spread the mashed turnip in a large glass baking dish that can hold all the turnip and sauce. Pour half of the cheeze sauce over the turnip and mix it in well, then pour the other half of the sauce on top. Bake at 425F for 25 minutes until the sauce is bubbling and the top is golden. Cool for 5 minutes and serve warm, on its own, as a side dish to a holiday meal, or over pasta or rice.