Flammekueche (Bacon and Onion Flatbread)

Instructions

Stir the ¼ cup flour, the warm water, the sugar and the yeast together in a small bowl. Cover it tightly and leave it somewhere warm for 30 minutes, until the starter is light and bubbly. Then mix in the beer and the milk.

Put the 2 cups flour and the 1 tsp salt in a food processor. With the motor running, pour the yeast mixture in through the feeding tube and process until the dough gathers into a ball. If it seems too wet or too dry, add a very small amount of extra flour or milk.

Keep processing the ball for 45 seconds to 1 minute, until it is smooth, elastic and warm. Transfer it to a buttered medium bowl and turn it to coat it with butter. Cover and leave it in a warm place until doubled, then punch it down and let it rise a second time.

While the dough rises, heat 1 tablespoon of the oil in a nonstick skillet. Cook the onion over low heat, stirring, for about 5 minutes until golden brown, then let it cool.

Mix the crème fraîche with the ½ tsp salt, the pepper and the nutmeg, then stir in the cooled onion. Heat the remaining oil in the skillet and fry the bacon, stirring constantly, until lightly browned. Drain it in a strainer.

Preheat the oven to 450 °F (220 °C), or as hot as it will go. If you are using a pizza stone, give it at least 30 minutes to heat.

Lightly oil a 14 x 16 inch (35 x 40 cm) baking sheet. Roll the dough out to a rectangle just smaller than the sheet and lay it on the sheet. With a pizza stone, roll the dough onto parchment paper instead.

Spread the onion and crème fraîche mixture over the dough, leaving a very small raised rim around the edge, and scatter the bacon on top. Bake for 4 to 20 minutes, depending on your oven, until the surface is lightly browned and bubbling. Blackened edges are traditional. Serve very hot.