Beat the roulades flat. Salt and pepper, brush with mustard and top with bacon, cucumber quarters and onion wedges. Roll up and tie. Fry all over in the oil, remove. Fry the onion cubes and the pepper strips in the oil, then fry the mustard for the sauce until a dark crust forms on the bottom of the pan. Deglaze these with cucumber liquid. Mix the meat stock with water and pour in. Put the roulades back in. Bring to the boil and place on a low flame, simmer gently for about 1 hour.
Remove the meat from the sauce and keep warm. Remove the pepper strips with a slotted spoon, puree some of them and put them back into the sauce. Refine with cream, season carefully and thicken with a sauce thickener, if desired.
Serve the roulades with the remaining strips of paprika. It goes well with dumplings and red cabbage.