Preheat your oven to 350ºF. Line a baking sheet with parchment paper for easy cleanup.

In a medium bowl, combine the Pecorino Romano and Parmigiano Reggiano cheeses. Set aside.

Spread ¾ cup of the shredded cheese mixture into 12 1-tablespoon piles on the parchment-lined baking sheet, spacing them evenly.

Using a mandoline or a very sharp knife, slice the Yukon gold potatoes into ⅛-inch-thick rounds for even cooking.

Transfer the sliced potatoes to a large bowl. Add the melted butter, minced garlic, lemon zest, kosher salt, and black pepper. Toss with your hands until all the potato slices are thoroughly coated.

Layer the potato slices on top of the cheese piles, starting with the largest slices at the bottom and finishing with the smallest at the top to create 1 ½-inch stacks.

Top each stack with another tablespoon of the cheese mixture for a golden, crispy finish.

Bake in the preheated oven for 30-35 minutes, or until the potatoes are fork-tender and the cheese is beautifully golden brown.

Allow the stacks to cool on the baking sheet for 5 minutes, then carefully transfer them to a serving platter. Garnish with more freshly ground black pepper, parsley, and a sprinkle of flaky sea salt. Serve warm and enjoy!