Preheat the oven to 60 degrees, preheat the plate and plate.
Cut the meat into approx. 1.5 cm cubes. Peel and finely chop the onion. Pepperoni in fine strips, slice mushrooms.
Let the butter get hot in a frying pan. Fry the meat in portions all around for approx. 2 minutes, remove, season, keep warm. Reduce heat, dab on cooking fat.
Let a little fried butter warm up in the same pan. Steam the onion. Steam the peppers, garlic and mushrooms until the resulting liquid has boiled down. Pour in the wine, stock and tomato paste, bring to the boil, reduce the heat and simmer to half.
Cut the pickle into strips and stir in with the sour cream . Add the meat, just let it get hot, season, place on the preheated plate.