Prepare the noodles according to the package directions. Reserve a cup of the pasta water for thinning the sauce later, if desired. Drain, toss with a bit of oil to prevent sticking and keep warm until the sauce is ready.
In a wide heavy-bottomed pan (cast iron is ideal), heat the olive oil over medium heat. Sauté the onions for 2 minutes, until softened. Add the mushrooms, stirring occasionally to prevent burning and for even cooking. Some browning should start to happen after about 5-8 minutes. Add the garlic and thyme, cooking for another 2 minutes. Deglaze the pan with the wine.
In a high-speed food processor or blender, blend the cashews, vegetable stock, miso paste and tomato paste until smooth. Pour into the mushroom mixture. Lower the heat, and bring to a simmer taking care not to burn it. Whisk in the nutritional yeast, if using. If you'd like to thin the sauce, add some pasta water or soup stock a half cup at a time. Once ready to serve, whisk in the mustard. Season with salt and pepper, if desired.
Combine the cooked, drained pasta with the sauce. Serve with almond ricotta and fresh parsley, if desired.
To quick soak the cashews: place the cashews in a small pot and cover with water. Bring to a boil, then reduce the heat and simmer for 10 minutes. Keep an eye on the water level so they don’t dry up and burn. Drain and use in recipe.*use gluten-free noodles and gluten free miso for a gluten-free meal