Chop the onion and add it to a pan with some olive oil and a splash of water.
When the onion becomes translucent add the dry rice to toast it, lower the heat to avoid burning the onion.
In the meantime peel the orange skin avoid scraping any of the white that would result bitter, set aside.
Squeeze and filter the juice, set aside.
Julienne the orange skin to make some fine zest of it.
Add it to boiling water for about 2min.
Drain and set aside.
Back to the rice now, when it's toasted add the white wine and turn up the heat to let it evaporate.
When the wine is almost completely evaporated, add the juice.
Add also the stock and bring to boil again. Keep adding stock until the rice is almost cooked. Adjust salt and pepper to taste.
Few minutes before the rice is done, add the peeled raw prawns to it.
Add the orange zest as well and stir together for a couple of minutes.
When the rice is cooked turn off the heat and add the butter
Add also the parmesan and stir together. Let rest for few minutes to help amid, butter and parmesan develop the typical risotto creaminess.
Plate and decorate with few other orange zest. If you want you can also add some chopped chives on top. Enjoy!