Peel potatoes and cut into eighths. Place in a large pot of cold water and cover and store in the fridge overnight.
Place potatoes in a large pot, and fill with fresh cold water. Bring to boil. When potatoes are soft and easily pierced by a fork (roughly 15 minutes), drain potatoes.
Add potatoes to a stand mixer along with butter and mix with whisk attachment on medium for 2-3 minutes, or until smooth.
Add roasted garlic, heavy cream and salt and pepper. Mix until incorporated.
Serve with melted butter and parsley or turkey gravy.
Notes
To serve the next day, place potato mixture in a thick-bottomed baking dish. Top with ¼ cup of cream and 4 pats of butter. Cover. Reheat in the oven at 375 for 25 minutes, stirring before serving.