Step 1

Peel and cut 4 medium russet potatoes into 1-inch cubes. Place the potatoes in a large pot and add enough cold water to cover potatoes by 1 inch. Stir in 1 tablespoon of the kosher salt. Cover and bring to a boil over high heat. Uncover and reduce heat to low to maintain a gentle simmer. Cook until potatoes are easily pierced with a knife but not falling apart, 12 to 14 minutes. Meanwhile, line a baking sheet with paper towels.

Step 2

Drain the potatoes, then transfer onto a baking sheet and spread into a single layer. Pat the potatoes dry with more towels and let cool for 10 minutes. Meanwhile, mince 2 garlic cloves, coarsely chop the leaves from 1/2 bunch fresh parsley, and finely shred 1 ounce Parmesan cheese (about 1/2 cup). Microwave 4 tablespoons unsalted butter in a large microwave-safe bowl until melted, about 30 seconds. Add the garlic, parsley, 1/2 teaspoon black pepper, and the remaining 3/4 teaspoon kosher salt, and stir to combine. Set aside.

Step 3

Heat 2 tablespoons olive oil in a 10-inch cast iron or nonstick skillet over medium-high heat until shimmering. Working in batches if needed, add the potatoes and cook, stirring and flipping them often, until golden-brown and crisp on all sides, 10 to 12 minutes total. Transfer the potatoes into the bowl of garlic butter and toss to coat. Transfer into a serving bowl and garnish with the Parmesan.