How to Make It
Place potatoes in a large saucepan, and add cold water to cover by 1 inch. Add garlic cloves and a generous pinch of salt, and bring to a boil over high. Reduce heat to medium-high, and simmer, uncovered, until potatoes are fork-tender, 10 to 12 minutes. Drain, and let stand at room temperature until potatoes look dry and chalky, about 10 minutes.
While potatoes dry, bring heavy cream and butter to a gentle simmer in a small saucepan over medium, stirring occasionally, until butter is melted, about 5 minutes. Remove from heat. Press potatoes and garlic cloves through a ricer, and return to saucepan. Fold cream mixture into potatoes.
Return saucepan to heat over medium-low. Add cheese in batches, stirring after each addition until cheese is fully melted and incorporated. Sprinkle with salt to taste.