Using a strong chef's knife, and perhaps a rubber mallet to help, cut the acorn squash in half, lengthwise, from stem to end. Use a spoon to scoop out the seeds and stringy stuff in the center of each half. Place each half in a baking pan, cut side up. Add about a 1/4 inch of water to the bottom of the baking pan so that the skins don't burn and the squash doesn't get dried out.
Place all ingredients into the Vitamix container in the order listed and secure lid.
Select Variable 1.
Turn machine on and slowly increase speed to Variable 10, then to High.
Blend for 4-5 minutes or until heavy steam escapes from the vented lid.
Season to taste with salt and pepper.
Recipe by Dr. Hagmeyer at https://www.drhagmeyer.com/vitamix-acorn-squash-soup/