Boil potatoes whole until completely cooked through, approximately 30-40 minutes
While potatoes cook, place heavy cream, grated garlic, thyme, bay leaf, and Parmesan rind in a small pot over low heat
Heat cream mixture until small bubbles appear around the rim, maintaining a gentle steep without simmering or boiling for about 20 minutes
Remove and discard aromatics from cream mixture, keeping it warm
Peel cooked potatoes and pass through a ricer or mash to desired consistency
Work butter into the mashed potatoes
Gradually add warm cream mixture in increments until desired consistency is reached
Stir in grated Parmesan cheese
Taste and adjust seasoning with salt and white pepper as needed
Top with fresh chives before serving
