Wash the potatoes and cook in boiling salted water for about 20 minutes. In the meantime clean and wash broccoli, divide into small florets and drain. Clean, clean and halve the mushrooms.
Wash the schnitzel and dab dry. Whisk the egg. Pull the schnitzel through flour, egg and breadcrumbs one after the other. Drain potatoes, quench and peel. Quarter potatoes lengthwise. Heat 1 tablespoon of oil in a coated pan and fry the potatoes in it for about 10 minutes at medium heat.
Season with salt and pepper. In the meantime peel and finely dice the onion. Heat 1 tablespoon of oil in a saucepan and sauté the onion. Add broccoli and mushrooms. Add broth and stew covered for about 8 minutes.
In the meantime, heat the remaining oil in a frying pan and fry the escalopes in it for about 6 minutes, turning them until golden brown. Stir the cream with the sauce thickener until smooth and bind the vegetables with it. Bring to the boil, season to taste with salt and nutmeg.
Arrange cutlets with broccoli and mushroom vegetables on a plate and garnish with lemon slices and parsley. Serve fried potatoes separately.