Pour meat broth in a saucepan and heat until boil. In another pan pour a spoonful of olive oil and 20 g butter. Peel the onion and cut it into very small pieces. Add the onion to the pan with the butter, lidding it, and let it soften a very slow fire for about 5 minutes, but without changing its color. Pour the rice into the pan and fry it lightly, but without getting golden. Pour rice with white wine and let the fire about 3 minutes to evaporate the alcohol. Pour 1 ladle of hot broth. Add more liquid as rice absorb it. Simmer for about 13 minutes. Add diced feta cheese Fontina cheese and crushed others. Let the meat on the stove for 5 minutes. At the last moment add the feta cheese Mascarpone or thick cream. Stir very well finished risotto with a wooden spoon. * For 6 servings.