Soak the cashews in water overnight. This is extremely important to a creamy sauce., Drain the cashews before blending.
Cook the onion and 1 cup of broth over medium heat for about 8 minutes until onion is very tender (cover pan and watch so the broth doesn’t boil away before the onion is cooked. You want to be able to mash it with a fork.) Add the garlic cloves, continue cooking until all the garlic is mashable. Add broth as needed, so it doesn’t burn but the broth should be cooked out…no more liquid, just a “mashable” cooked onion and garlic.
Put onion & garlic in high speed blender or magic bullet.
Add ½ cup broth and cashews, lemon juice and nutritional yeast.
Blend on high until very creamy.
Add more broth to desired consistency and salt and red pepper or white pepper to taste. If you are making a soup thin with more broth or coconut oil to soup consistency.
Sauce will thicken in fridge or freezer. .
Thin to desired consistency with broth or coconut milk. Thicker for an Alfredo sauce, Beef Stroganoff sauce or Mac & Cheese sauce. Thinner for soup.