Prepare the ingredients: cut bacon into small cubes. Cut onions into thin slices and sprinkle them with a pinch of salt (they will soften and not burn in a hot oven). Add the creme fraiche into a small bowl, season it with salt and pepper, and stir until combined.
7 oz (200g) thick-cut bacon or German Speck, 1 small/medium onion, 1/2 cup (150g) creme fraiche
Roll out the dough very thinly into an oval or rectangular shape and place it on a baking sheet lightly greased with olive oil/vegetable oil.
Spread the creme fraiche over the dough leaving some border, top with bacon and onion slices (if they released some water, squeeze it out).
Bake the Flammkuchen for about 10-12 minutes or until golden brown. The baking time may be longer (up to 15-18 minutes) if your oven is not as hot as mine.
Sprinkle with thinly sliced chives (optional).
Cut into squares and enjoy!