This was borrowed from Alton Brown, and became a HUGE hit for us.
3 1/2 pounds russet potatoes
2 tablespoons kosher salt
16 fluid ounces (2 cups) half-and-half
6 cloves garlic, crushed
6 ounces grated Parmesan - (this is the secret sauce!)
1. Peel and dice potatoes, making sure all are relatively the same size. Place in
a large saucepan, add the salt, and cover with water. Bring to a boil over medium high heat and then reduce heat to maintain a rolling boil. Cook until potatoes fall apart when poked with a fork.
2. Heat the half-and-half and the garlic in a medium saucepan over medium heat until simmering. Remove from heat and set aside.
3. Remove the potatoes from the heat and drain off the water. Mash and add the garlic-cream mixture and Parmesan; stir to combine. Let stand for 5 minutes so that mixture thickens and then serve.