Stuffed Rump Steak or Carpet Bag Steak, with Rissolè Potatoes

For the stuffed steak

• Cut the meat sideways with a sharp knife like a pocket. Mix the diced ham and drained flaky mushrooms with a peeled, diced onion. Chop the parsley. Add with the chervil.
• Peel and chop the second onion, mix with the ground beef, egg yellow, salt and pepper. Stuff the steak first with the beef, then with the ham mixture. Now close the cut well (either sew it up with kitchen thread or use beef needles or toothpicks)
• Let the oil get smoky hot in a pan. Fry the steak pocket briefly on all sides. Preheat the oven to 100 degrees and leave the steak there for about 40 minutes. (Use a terhmometer!) Since the steak is very thick, it needs more roasting time than usual
• Serve with rissole potatoes. i.e., peel the amount of potatoes according to taste and cut into small cubes, rinse, pat dry with kitchen paper. Let the oil get hot in the pan and fry the potato cubes on all sides (turning them constantly). Before the end of the cooking time, add the finely chopped onion, fry but do not brown.
• Shortly before the end of the cooking time, season the potatoes with salt and pepper. Take the roast out of the oven, wrap it in aluminum foil and let it rest for about 5 minutes. Then carefully cut into slices and serve with the potatoes. Since the abundance is also "full", there is no need for a side dish.