A bunch of potatoes
Salt and pepper
Roast garlic at 350 for 20 minutes.
Start potatoes in cool salted water, boil them, drain water well. Put through food mill, meat grinder, ricer, masher, or mixer with roasted garlic. Don't over-whip or they'll get gluey and shiny. Mix them as little as possible. Add butter and milk or cream, ratio 1:3. Salt and pepper to taste.
Source: Thanksgiving Dinner class, PA Culinary Institute, Chef Don Hutchins, 11/12/06