Divide a head of cauliflower into florets that are all roughly the same size.
Steam cauliflower pieces over boiling water (15 to 20 minutes), or until the cauliflower is tender. Drain the cauliflower and toss it in a bowl of ice water to bring the cooking process to a screeching halt.
When the cauliflower has cooled, put the florets in a food processor along with 1/2 cup of water. Puree the cauliflower on high speed until smooth, but with some very small pieces of cauliflower remaining in the mix for just a bit of texture.
Pour all of the pureed cauliflower into a medium sauce pan.
Add the cream, salt, white pepper, garlic powder and onion powder to the cauliflower and stir. Set the saucepan over medium heat and cook, stirring often, for 5 to 10 minutes, or until thick.