Onions peel, halve and in strips cut. Dab meat dry with kitchen paper. Season with salt and pepper and spread with mustard. Add a piece of cucumber and some onion each. Roll up meat slices firmly and fix them with wooden skewers. Heat clarified butter in a roaster.
Fry the roulades in it until golden brown all around. Add the remaining onions and tomato paste and braise briefly. Deglaze with 1/2 litre water. Season stock with salt and pepper. Cover and braise for about 30 minutes. In the meantime clean, wash and halve the mushrooms. Add to the roulades and cook covered for another 20 minutes. During the last 10 minutes add about 1/4 litre of hot water. In the meantime, peel, wash and dice the potatoes for the puree. Cook in boiling salted water for about 20 minutes. Then drain.
Add to the roulades and cook covered for another 20 minutes. During the last 10 minutes add about 1/4 litre of hot water. In the meantime, peel, wash and dice the potatoes for the puree. Cook in boiling salted water for about 20 minutes. Then drain. Add milk and fat to the potatoes and mash. Flavour with nutmeg. Stir flour in a little cold water until smooth. Thicken the sauce stock while stirring constantly. Season again with salt, pepper and a little mustard. Serve the puree, roulades and sauce sprinkled with lightly crushed pink berries and garnished with chervil
Add milk and fat to the potatoes and mash. Flavour with nutmeg. Stir flour in a little cold water until smooth. Thicken the sauce stock while stirring constantly. Season again with salt, pepper and a little mustard. Serve the puree, roulades and sauce sprinkled with lightly crushed pink berries and garnished with chervil