Wash the potatoes and cook covered for about 20 minutes. Clean the savoy cabbage, cut into quarters, wash and cut into fine strips. Peel onions and dice very finely. Chop cucumbers. Mix half onions, gherkins and mustard
Dab the roast beef slices dry and spread a thin layer of the mustard mixture on them. Roll them up and wrap 1 slice of bacon around each
Heat 1 tablespoon of butter in a saucepan. Fry the remaining onions in it. Braise the savoy cabbage briefly. Season with salt and pepper and add approx. 1/8 l water. Steam covered for about 15 minutes.
In the meantime, rinse the potatoes and peel the skin. Fry the potatoes in 1 tbsp. hot butter at medium heat until golden brown. Turn from time to time. Season with salt and pepper. Wash the thyme, chop coarsely, fry briefly
Heat the oil. Fry the rolls in it thoroughly all around. Season with a little salt and pepper. Deglaze with 200 ml water. Add cream and brandy, bring to the boil. Cover and braise over medium heat for about 5 minutes
Stir the sauce thickener into the roulade stock. Bring to the boil again briefly and season to taste. Serve everything