Risotto with Orange and Parmesan

Wash the orange. Grate its zest (only the orange, non-bitter part) and squeeze out its juice. Sweat the onion in equal parts oil and butter together with the sprig of rosemary. Add the rice, salt it and blanch briefly. Deglaze with the white wine. Pour in the water and leave to simmer over moderate heat, stirring from time to time. Halfway through cooking add the orange zest, and toward the end the orange juice. Immediately after removing from the heat, sprinkle with the grated parmesan.