You can try replacing the cashews with a different nut or seed, but note that the consistency, flavor, and color may be affected. Cashews not only add richness to this recipe, their natural starch content also makes the sauce creamy (in addition to the oats). If you need a nut-free cheese sauce, this Oil-Free Vegan Queso can be made with soaked, raw sunflower seeds instead of cashews. And this Vegan Mac and Cheese uses a nut-free cheese sauce that was inspired by this recipe.