Use a slotted spoon to add the cashew nuts to a blender. Measure out 1/3 cup of the cooking liquid and add it to the blender. Add the nutritional yeast, soy sauce, apple cider vinegar, salt, black pepper, and half of the caramelized onion mixture.
Blend until very smooth. If your blender is having trouble spinning, you can add a little extra cooking liquid from the cashews to help it out.
Garnish with minced parsley and paprika and serve your vegan French onion dip with bread, chips, or vegetable sticks .