If you cut the meat yourself, cut it into strips approx. 3 - 4 cm thick. Cut open the veal kidneys horizontally and sideways and cut out the ureters. Wash the kidneys thoroughly under running water, then chop them up as well.
Clean the fresh mushrooms and then cut in half or quarter. Drain the mushrooms from the tin. Peel the onion and cut it into small cubes.
Heat the oil in the pan over high heat. Add the chopped meat and the kidneys and fry for 10 minutes. Then add the mushrooms and the onion and cook for 5 minutes, then add the white wine.
Season to taste with salt and pepper. Whisk the cream with the starch and bind the strips with it.
Tip: If you don`t like kidneys, you can of course replace them with veal.