In a small saucepan, cover the lentils with water and place the pot over medium-high heat. Bring the lentils to a boil and then simmer until just-tender, about 20 minutes. They will continue to cook in the bolognese later on. Drain the lentils and set aside.
In an upright blender, combine the cashews and water. Blend on high until you have a totally liquified cashew milk. Set the milk aside.
You’ll need to finely chop the mushrooms, and a food processor is the easiest way to do it. Cut the mushroom caps into quarters and place half of them in the food processor. Pulse the food processor about 8-10 times or until mushrooms are finely minced. Transfer minced mushrooms to a large bowl and repeat pulsing process with remaining mushrooms. You can also mince them by hand if you prefer.
Heat a large, heavy pot (like a dutch oven) over medium heat. Pour the oil into the pot once it’s warmed up. Add the onions to the pot and cook, stirring often, until softened and translucent on the edges, about 5 minutes. Then, add the chili flakes, garlic, bay leaf, and beets. Cook this mixture for 8 minutes. The beets should keep the pot sufficiently moist without the need to add water/more oil.
Add all of the mushrooms to the pot and stir to combine all of the vegetables. Leave the vegetables alone for one minute. Then, stir the vegetables again. Let them sit for another minute. After this, the mushrooms should be letting off liquid. Add the cooked lentils, miso, and tomato paste to the pot. Season everything generously with salt and pepper and stir to combine.
Keep cooking the vegetables until there’s only a small amount of liquid weeping out and everything is quite brown and reduced, about 10-12 minutes. Continue stirring the mixture throughout the cooking process.
Add the red wine to the pot and stir. Let the mixture simmer and cook out for 5 minutes, stirring often. There should still be a good slick of liquid in the pot at the end of the 5 minutes.
Add the crushed tomatoes to the pot and stir to combine. Let the mixture simmer for another 5 minutes, stirring often. At this point the bolognese should be like a very thick stew. Add the cashew milk to the pot and stir. Bring the bolognese to a boil and then simmer for 5 minutes, stirring often. Check the bolognese for seasoning and adjust if necessary. Keep it warm while you cook the pasta.
Cook the pasta according to package directions minus 1-2 minutes. You want to finish cooking the pasta in the bolognese. Once pasta is sufficiently cooked, drain and add it to the pot with the bolognese. Add the chopped parsley as well. Gently fold the pasta and bolognese to combine and heat throughout. Serve mushroom and beet bolognese immediately.