Peel, wash and halve the potatoes and cook them in salted water for about 25 minutes until soft. Peel and wash carrots and cut into cubes. Clean the leek, cut into rings and wash. Blanch carrots in boiling salted water for 3-4 minutes, add leek after 1-2 minutes.
Drain the vegetables and rinse with cold water. For the béchamel, melt 25 g butter in a saucepan. Stir in 25 g flour and sauté briefly. Stir in cream and stock and simmer for about 1 minute while stirring.
Season the sauce with salt, pepper and nutmeg. Add vegetables to the sauce and heat again. Wash the meat, pat dry, cut in half and tap very thinly between 2 layers of foil. Whisk eggs in a deep plate and season with salt and pepper.
Turn escalopes one after the other in 3 tablespoons of flour, egg and breadcrumbs. Heat clarified butter in a large frying pan and fry escalopes in portions for approx. 6 minutes while turning them until crispy. Bring milk and 1 tablespoon butter to the boil.
Drain the potatoes. Add hot milk and mash. Season puree with salt, pepper and nutmeg. Wash herbs, dab dry and chop or chop. Stir the herbs, except for some chives for sprinkling, into the puree.
Arrange cutlets on the creamed vegetables, sprinkle with cress and garnish with lemon slices. Sprinkle the puree with chives and serve.