For the orange butter, bring the orange juice to the boil and reduce by half. Wash the orange hot, grate dry and peel thinly with a zest ripper. Coarsely chop the green pepper.
Stir pepper and orange zest into the butter. Stir in orange juice. Season with salt. Form butter into a roll, wrap in foil and chill. Peel onion and garlic and chop finely.
Clean and clean the mushrooms and cut them into slices. Heat 1 tablespoon of oil in a saucepan. Fry the onion, garlic and mushrooms over a low heat until transparent. Add rice and sauté briefly. Season with salt and pepper.
Gradually add broth and wine, stirring from time to time. Always add the next portion of liquid only after the rice has absorbed the liquid. Cook for a total of 30-35 minutes. Wash the meat, dab dry and cut into 8 medallions.
Heat 2 tablespoons of oil in a frying pan. Fry the meat on each side for about 4 minutes. Season with salt. Cut the orange into 8 slices and fry briefly in the frying fat. Cut off 4 slices of butter and use the remaining butter for other purposes.
Arrange meat, orange slices, orange butter and risotto on plates.