Season the meat with salt and pepper, heat the olive oil in a pan and fry the meat in it. Add the garlic, onion and mushrooms and sauté. Stir in the mustard, dust with flour and deglaze with the meat stock. Add sour cream and soy sauce and simmer for 20 minutes, add parsley and season with salt and pepper if necessary.
Cook the vegetables in the vegetable stock and the rice in salted water. Add the vegetables to the rice and stir everything together.