Peel onions, cut in half and diagonally into half rings. Quarter peppers, clean and cut diagonally into strips. Halve cucumbers lengthwise, squeeze out sauerkraut, stir through with crème fraîche (1), season with salt and pepper.
Season roulades on both sides with salt and paprika powder. Spread a slice of bacon and the sauerkraut evenly on each. Place half a cucumber on one end, roll everything up. Put the roulades together, fry them in hot oil all around. Cut the remaining bacon into strips.
Take out the roulades, put the bell pepper strips, onions, bacon and marrow in the cooking pot, sauté briefly. Fill up with the clear soup. Add roulades repeatedly, cook for 15 min at low temperature with lid closed. Remove roulades. Add crème fraîche (2) to the sauce, season with salt and pepper. Sprinkle in sauce binder and let it bubble up.