How to Make It
Preheat oven to 425°F. Combine cream and garlic cloves in a small saucepan; bring to a simmer over medium-low, stirring occasionally. Continue cooking, stirring occasionally and maintaining a low simmer, until cream is reduced to about 1/2 cup, about 20 minutes. Remove from heat; stir in 1/4 teaspoon salt. Using an immersion blender, pulse mixture until smooth, about 20 pulses. Season with salt to taste; set aside. Mixture will thicken as it stands.
Toss together potatoes, oil, pepper, gochugaru, and remaining 1/2 teaspoon salt on a rimmed baking sheet; spread potatoes in a single layer. Bake in preheated oven until tender, 8 to 10 minutes. Set aside.
Place a cast-iron pizza pan or pizza stone on middle oven rack; increase oven temperature to 500°F. Stretch 1 dough ball into a 10-inch circle, creating a thicker 1/2-inch border. Place on a pizza peel or parchment paper lightly dusted with cornmeal. Top dough with half of the cream mixture, half of the potatoes, half of the mozzarella, and half of the cheddar, leaving a 1 1/2-inch circle without toppings in center.
Slide pizza from peel onto preheated pizza pan or stone. Bake at 500°F until cheese is melted and crust is browned in spots, 7 to 9 minutes. Transfer pizza to a cutting board; sprinkle with 1/4 cup bacon.
Cut pizza into 6 slices; top with 1/4 cup sour cream and 1/2 tablespoon chives. Serve immediately.
Repeat Steps 3 through 5 with remaining dough ball, cream mixture, potatoes, mozzarella, cheddar, bacon, sour cream, and chives.
If you don’t have a pizza peel, use a baking sheet to slide the pizza onto the pan or baking stone.