Peel and dice potatoes, making sure all are relatively the same size.
Place in a large saucepan 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.
Heat the half-and-half and the garlic in a medium saucepan over medium heat until simmering.
Remove from heat and set aside.
Remove the potatoes from the heat and drain off the water.
Mash and add the garlic-cream mixture, salt, and Parmesan; stir to combine.
Let stand for 5 minutes so that mixture thickens and then serve.