Clean and peel the carrots and celery and cut into fine strips. Clean, wash and cut the leek into fine strips. Wash rump steaks and pat dry. Season with salt and pepper and dust with flour. Heat oil in a pan and fry the steaks on both sides. Add beef stock and sour cream and braise the rump steaks in it for about 15 minutes at low heat. In the meantime, cut the gherkins into fine strips.
Cook the noodles in boiling salted water for about 8 minutes. Add the vegetable strips to the roast about 5 minutes before the end of the cooking time and cook them in it. Season with salt, pepper and lemon peel. Drain the noodles and stir in the fat. Arrange roast beef with sauce, vegetable strips and noodles on plates. Serve remaining noodles separately