Put 1/4" of water in a medium pot. Add cauliflower and garlic, cover. Bring to a boil and cook until cauliflower is easily pierced with a fork, approximately 8-10 minutes.
Drain well, put cauliflower and garlic in food processor.
Add milk, butter, salt and pepper. Puree until smooth, adding more milk if needed.
Season to taste with salt, pepper and chives.
Can be refrigerated up to 2 days, reheat before serving