In a skillet, saute garlic, shallots, and onions until translucent.
Add the wine and cook it down for about 5 minutes.
Add ½ cup vegetable broth, and continue to cook, reducing the heat to simmer.
In the meantime, combine the raw cashews (or substitute white beans, silken tofu, flour of choice, or gluten-free flour), nutritional yeast, garlic, onion powder, dijon mustard, and 1 ½ cups vegetable broth in a high-speed blender.
Blend until smooth.
Now, turn the heat up to medium on the pan with the onion mixture.
Slowly add the contents of the blender, whisking as you add.
As the mixture heats, it thickens.
Remove the white sauce from the heat and allow it to cook.