Heat the oil in a pan. Sauté the onion and garlic for approx. 3 mins., add the rice and sauté until translucent, stirring constantly. Pour in the wine and reduce completely. Add the courgette. Gradually add the stock, stirring frequently, so that the rice is always just covered with liquid, simmer for approx. 20 mins. until the rice is creamy and al dente. Mix the cheese, butter and lemon zest into the risotto.
Heat the oil in a non-stick frying pan. Fry the courgette for approx. 3 mins. on each side until golden brown, remove, season.
Season the fish fillets, place a sage leaf on each side, wrap with cured ham, secure with a toothpick if necessary. Heat the oil in the same pan, fry the fish for approx. 3 mins. on each side. Plate up the risotto with the courgette and saltimbocca.