Steam the cauliflower florets in a large pot for about 10-15 minutes, or until they are tender and easily pierced with a fork.
Drain the cauliflower well and transfer it to a large mixing bowl or a food processor.
Add the butter, heavy cream, garlic powder, onion powder, salt, and pepper to the cauliflower.
Blend or mash the mixture until smooth and creamy, adjusting the consistency with additional cream if desired.
Taste and adjust seasoning as needed.
Serve warm, garnished with fresh chives if using.