This is a conglomeration of recipes, so I'm calling it my own. It's the magic that happens when you read a half-dozen mashed potato recipes on epicurious.com the week before Thanksgiving. You could easily half this, as written it served 13 with only a couple cups leftovers.
Mashed Potatoes with roasted garlic, rosemary and parmesan
4 lbs red potatoes
4 lbs yukon gold potatoes
1 t salt
Wash, trim and cube potatoes (I peeled about 1/3 of them). Cook in salted water until they fall apart when pierced with a fork. Remove from heat and drain, reserving about 1 cup of water.
4 heads garlic (16 cloves), roasted
1 c milk, 2%
4 T butter
1 T fresh rosemary, minced
6 T parmesan cheese
Salt & pepper to taste (I started with 1 t salt and added from there)
Combine above in small saucepan and bring to a low simmer. I used an immersion blender to liquefy the garlic, you could also toss it into a blender. Mix into mashed potatoes, serve. Hope for leftovers.