This tangy, savory honey mustard potato tart makes the perfect, crowd-pleasing appetizer for your next holiday party.
Place the flour, salt, and sugar in the bowl of a food processor fitted with the steel blade. Pulse for a few seconds to combine.
Preheat the oven to 400 degrees and line a sheet pan with parchment paper.
Roll the dough between two sheets of lightly floured wax paper, slightly larger than 10 x 14 inches. Using a ruler and a small knife, trim the edges. Place the dough on the prepared sheet pan and refrigerate while you slice the potatoes.
Peel the potatoes and slice very thinly, about 1/8 inch. A mandolin is an ideal tool to slice the potatoes in thin, uniform slices.
Spread the rolled pastry with the mustard, right to the edges. Sprinkle with the onion and chives, then top with the cheese, again, right to the edges.
Place the potato slices over the cheese in diagonal lines, just barely overlapping and brush the potato slices with cream.
Dot with the butter and sprinkle with salt and remaining chives.