This is tasty and can be a base for your creations and modifications. Here’s an example in scalloped potatoes but you can use it for mac n cheese.
1 large sweet potato cooked, skin removed, using your preferred method (I cook in microwave for about 13 minutes depending on the size)
1.5 cups of non-dairy milk (I used unsweetened almond milk)
1/3 cup of nutritional yeast
1 tsp garlic powder
2 tsp onion powder
Put ingredients in blender (I use Vitamix) and blend on high until smooth, just a few seconds usually using the tamper. If too thick add a bit more water or more non-dairy milk. If you want to use a regular potato throw in 1 or 2 cooked carrots as well.