Prepare the cashews using one of these two methods:

SOAK OVERNIGHT:

1. Put the cashews in a bowl of room temperature water and soak them overnight.

BOIL THE CASHEWS:

1. Put your cashews in a pot and fill it with enough water to cover them.Then, bring the water to a boil and continue boiling for about 15 minutes. Drain and rinse the cashews, and they're ready for the recipe.

Preparing The Sauce And Noodles:

1. Drain cashews from the water and set them aside.
2. Bring a pot of salted water to a boil and follow directions on box to cook your fettuccine noodles.
3. Heat olive oil in a pan over medium heat. Add chopped onion and minced garlic to the pan and saute for about 3 minutes - the onion and garlic should be soft and translucent.
4. Transfer sauteed onion and garlic to a blender, along with drained cashews, nutritional yeast, vegetable broth, and plant milk. Blend at the highest speed for 1 minute until you have a smooth mixture. 
5. Pour the blended sauce back into your pan and cook on medium heat for about 2-3 minutes. The more you cook the alfredo sauce, the thicker it will get. Add in the chopped parsley towards the end of cooking the sauce.
6. Add cooked fettuccine to the pan and mix with the sauce. Or put the fettuccine on a plate and pour sauce over top.