Wash the roulades and pat them dry. Cut cucumbers into quarters. Peel onions and cut into fine slices. Spread the roulades with mustard, season with salt and pepper and cover each roulade with 2 slices of bacon.
Let one slice overlap each. Spread cucumber quarters and 1/3 of the onion slices evenly on one end of the roulades and roll up the roulades very firmly. Wrap with kitchen string. Heat clarified butter in a roaster.
Brown the roulades in it all around. Add the remaining onion slices and tomato paste to the roaster and fry briefly. Deglaze with 1/2 litre water. Cover and stew for about 40 minutes. Add another 1/4 litre of water and braise for another 40 minutes.
In the meantime peel, halve and wash the potatoes. Cook in boiling salted water for about 20 minutes. Clean and wash the beans, possibly cut them into smaller pieces. Cook in boiling salted water for about 15 minutes.
Mix flour and whipped cream until smooth. Remove the roulades from the sauce. Stir in the whipped cream. Bring to the boil while stirring and season to taste. Arrange everything together and garnish with parsley.