Frozen puff pastry is a busy cook’s best friend. It turns even the most basic ingredients into superstar toppings that can be mixed, matched, and adjusted to the occasion. In this case, caviar really pushes the luxe factor.
Mix together crème fraiche, orange zest, lime zest, and lemon zest in a small bowl. Season to taste with salt and pepper. Cover and refrigerate until serving.
Preheat oven to 425°F. Line a baking sheet with parchment paper.
Melt butter in a small saucepan over medium-low heat. Add rosemary and gently heat for 10 minutes to infuse flavor.
On a lightly floured surface, roll out puff pastry to a 10-inch by 14-inch rectangle and transfer to prepared baking sheet.
Use a paring knife to lightly score a border ½-inch away from the edge of the pastry. Use a fork to dock the pastry inside that border, every inch or so, to keep the center from puffing.
Brush 1 tablespoon of Danish Creamery Rosemary butter all over the center of the pastry. Toss the potatoes with remaining 3 tablespoons Danish Creamery Rosemary butter and a pinch of salt and black pepper. Arrange potato slices on the pastry, within the border, spread out evenly with the edges slightly overlapping.
Bake for about 30 minutes, or until pastry is puffed and golden and potatoes are crisp and starting to curl. Let cool slightly, then transfer to a wire rack to cool 10 more minutes.
Cut into 12 squares and serve with a dollop of citrus crème fraiche and spoonful of caviar.