Boil potato, carrot and onion together until soft, 10-15 minutes. You may need more water to cover.
To a blender add silken tofu, nutritional yeast flakes, lemon juice, salt, onion granuals, and garlic granuals.
Using a slotted spoon, add cooked carrot, onion and potato to blender with other ingredients. Pour in about half of the water.
Pureé on highest setting until velvety smooth, adding more cooking water as needed. Scrape down sides if needed a few times.
Taste, and adjust for salt. You can also add more lemon juice. Adding 1 TB brown mustard OR 1 TB miso is nice and changes the flavor profile, so add those if you like. The texture of this is great, and really mimics a "Processed" Cheese Sauce, but with healthy ingredients. Enjoy! :)