Soak the cashews for at least 3-4 hours. Otherwise, you can cover them with boiling water and soak for only approx. 15 minutes to speed up the process, or simply use cashew butter.
Prick the sweet potato a few times with a fork and microwave until soft, for 6-7 minutes. (Optionally, bake the sweet potato in the oven at 425°F for about 50-60 minutes). Afterwards, peel it and scoop out the flesh.
Cook pasta according to package directions in a salted pot of water.
While the pasta is boiling, in a pan over medium high heat, heat the oil. Add the onion, stir and let cook until translucent, about 5 minutes. Add garlic and roast for one minute longer.
Remove the onions and garlic from the pan and add it to a blender along with the soft sweet potato, cashews, nutritional yeast, smoked paprika, lemon juice, salt, and black pepper.
Blend it all together for 2-3 minutes, or until smooth and creamy. Add more water and seasonings until desired consistency and taste if necessary.
Pour the sauce into a large skillet or pan. Heat over medium heat while stirring for 2-3 minutes, or until hot and bubbly.
When the pasta is al dente, drain, add to the sauce and toss to combine. Cook for about 1-2 minutes until sauce sticks well to the pasta. (If the sauce gets too thick, add more water or plantbased milk to thin. For more creaminess, you can also add a little coconut cream).
Pan-fry mushrooms in a pan with some oil for 6-8 minutes until golden browned. Add garlic and roast for one minute longer. Season with salt and pepper to taste.
Serve your creamy pasta with roasted mushrooms and fresh chopped herbs to garnish and more yeast flakes/ vegan parmesan cheese if you like.