Preheat your oven to 425°F (220°C). Thinly slice russet or Yukon Gold potatoes to about ⅛-inch thickness and coat in a mixture of melted butter, garlic, kosher salt, and black pepper.

Layer the potato slices in a circular pattern in a cast-iron skillet or on a baking sheet, sprinkling grated Parmigiano Reggiano between the layers. Finish with a top layer of cheese.

Bake the assembled potato galette in the oven for 50-60 minutes until golden brown and crispy. Cover with foil if the top browns too quickly.

While baking, combine crème fraîche, dill, and lemon juice in a bowl. Mix until smooth, taste, and adjust seasoning. Refrigerate until serving.

Once the galette is golden and crispy, let it cool slightly, then invert onto a plate and sprinkle with flaky sea salt.

Spread the crème fraîche mixture on top, layer with smoked salmon, red onion, capers, and chives before serving.