Cook potatoes in microwave for 8 minutes.

Place onion, carrot, celery and cauliflower in a 2-quart (1.9 l) saucepan and cover with water.

Bring to a boil. Reduce heat to medium and cook until tender.

Set aside 1 heaping cup of cooked vegetables.

Place remaining vegetables, bouillon, potatoes, and milk into the Vitamix container and secure lid.

Select Variable 1.

Turn machine on and slowly increase speed to Variable 10, then to High.

Blend for 3 minutes using the tamper to press the ingredients into the blades. Reduce speed to Variable 2 and remove the lid plug.

Add reserved vegetables and water through the lid plug opening.

Blend an additional 5 seconds. Serve immediately.