Cut the meat into bites and pour them with the oil in an aluminum tray. The aluminum tray will make the dish much tastier because it will actually get a nice crisp. Nonstick containers don't provide that nice crispy flavor that makes the dish as delicious.
Put the tray in a preheated 392°F (200 °C) oven for the meat to cook. Once it begins to redden, pour in the roundly sliced leeks and stir well. Cook until they soften and season with black pepper.
Add the roundly sliced mushrooms, stir again and bake until the mushrooms are ready. Once they soften and begin to braise, add the finely chopped herbs and spices, salt to taste and sprinkle with paprika.
Bake another 5 min.