1. Preheat oven to 425°F.
2. Cut the bacon in small strips. Peel and cut the white onion in small dices. Rinse and drain the sauerkraut; press out water as much as possible.
3. Unroll the refrigerated Flatbread Dough with included parchment paper onto baking tray.
4. Spread sour cream over the dough sheet, leaving ½ in. on each edge. Top with diced onions and bacon and add salt and pepper to taste.
5. Bake for about 12 minutes. Add sauerkraut and marjoram and continue baking for about 3 more minutes. Serve warm.