The night before, put your cashews in a bowl of water. If you forget then you can add them to boiling water for about 10 minutes.
Bring a large pot of water to the boil and add your spaghetti (or other pasta shapes)
Water sautee the chopped onion until translucent.
Add garlic and Mushrooms and cook until soft.
Blend the cashews and soy milk. Add to the pan with the vegetables. Add the nutritional yeast, spices, and salt and pepper to taste.
Cook for around 5 - 10 minutes, the sauce will begin to thicken. At this point you may need to add some more milk.
Add the spinach and cook until wilted.
Drain the pasta and stir in the sauce.