In a large saucepan, cover cauliflower with water. Bring to a boil over medium-high heat. Reduce heat to low. Simmer, covered, until cauliflower is tender, 10-12 minutes; drain and return to pan.
Meanwhile, combine remaining ingredients in a small saucepan. Bring to a simmer over medium-low heat. Immediately remove from heat and strain through a fine mesh strainer; discard peppercorns, garlic and bay leaf.
Add cream mixture to cauliflower. Mash to reach desired consistency.