Briefly sweat the onion cubes in oil, add the garlic and rice and sweat through, stirring constantly. Deglaze with wine. Only when this has boiled over, pour in the hot broth ladle by ladle, stirring again and again. As soon as the rice is cooked (after approx. 25 minutes), it should still have a bite, stir in the lemon zest and juice, butter, parmesan and parsley and season the risotto with salt and pepper.