Pizza dough is rolled paper-thin, spread with a silky creme fraiche-nutmeg-egg yolk base, scattered with bacon and leeks, topped with Gruyere, and baked on a pizza stone at 550 degrees until blistered and charred at the edges. This Alsatian flatbread is a stunning savory addition to a holiday party spread, offering a crispy, creamy, smoky bite that rivals any pizzeria.