1. Preheat the oven to 180°C (356°F).
2. Finely chop the mushrooms and onion and squeeze the garlic clove through a garlic press. Cut the bacon slices into small pieces.
3. Heat the oil in a pan and fry the bacon for three minutes. Add the onion, mushrooms and garlic and fry for four minutes. Turn off the heat and place the mixture in a colander so that the liquid can drain.
4. In the meantime, finely chop the walnuts and parsley and place in a dish. Stir the drained mushroom mixture through the walnuts and parsley.
5. Place the sirloin of veal on the counter. Slice the sirloin of veal not quite all the way in half and slice the opened halves not quite all the way through once again from the middle. Open the halves again to the outside so that you have a flat piece of meat. Place the sirloin between plastic wrap and pound with a heavy pan until it is thin. Sprinkle with a little salt and pepper. Spread the filling over the meat and then roll it up tightly. Bind the meat in four places with butchers twine.
6. Heat the butter in a frying pan and brown the roulade on all sides in ten minutes. Place the meat in an ovenproof dish, pour the jus from the pan over the meat and place the dish in the oven for approximately 30 minutes at 180°C (356°F).
7. Remove the veal roulade from the oven, cover with aluminium foil and let it rest for ten minutes.
8. Slice the roulade into thin slices and serve with, for example, oven-baked potatoes and blanched green beans fried in garlic.

Enjoy your meal!

Source: Laura's Supervood