Chop cauliflower into florets and add to a stockpot with cashews and garlic (peeled and ends removed). Cover with water and place over high heat. Boil the mixture for 20-30 minutes until the cashews and cauliflower are very soft.
In a sauté pan, heat the olive oil and butter (feel free to use vegan butter) over medium-high heat. Once hot, add the mushrooms and cook until all the water has evaporated and the mushrooms begin to brown. Add the Italian seasoning to the mushrooms and cook until fragrant and slightly softened — about 2 minutes.
Put a large stockpot filled ¾ of the way with water over high heat. Once boiling, add fettuccine noodles and cook according to the package instructions for al dente.
By now, your cauliflower mixture should be softened. Reserve a cup of cooking water. Strain the mixture and add it to a blender along with nutritional yeast, 1 teaspoon of salt, and ¼ cup of cooking water and blend the mixture until very smooth. Add more cooking water if the mixture is too thick and add additional salt if needed.
Add the cauliflower Alfredo sauce to the mushrooms and mix. Add the non-dairy milk and 1/2 C of pasta water.
By now, your fettuccine should be cooked. Reserve 3 C past water and strain the fettuccine. Add the strained noodles to the sauce and mix well using tongs. Add more pasta water if the pasta needs additional moisture, adding 1/4 C at a time until the sauce is creamy and smooth.
Serve with vegan parmesan. Save leftover pasta water to toss with leftovers when reheating. Bottoms up!
For the Alfredo Sauce:
1 medium-sized head of cauliflower (try to use organic, I find non-organic cauliflower to be MASSIVE)
1 1/4 cup of cashews
2 cloves of garlic, peeled
16 oz of mushrooms
1/4 cup of Italian seasoning
1 tbsp sherry cooking wine or dry white wine
3 tablespoons of butter (or vegan butter)
2-3 tablespoons of olive oil
1/2 cup nutritional yeast
1/4 C cooking water
1 C non-dairy, non-flavored, unsweetened milk (preferably one that's very thick and creamy)