Add the zest of a lemon plus half the juice to the stock. Set aside.
In a pan melt 2 tablespoons of butter and add your onion and garlic, let it cook until the onion is translucent.
At this point add the rice and stir, make sure every grain is covered with the butter.
Once the edges of the rice start to become translucent add 1 ladlefuls of stock and stir.
Once it has almost completely been absorbed add another ladleful and stir again.
Keep doing this until the rice is cooked. The rice should never be dry, there should always be some stock in there, it should take around 17minutes to cook.
Once the rice is cooked add in one last ladleful of stock, some parsley, your prawns and Parmesan, the juice of the other half of the lemon and stir
Stir in some butter before serving and garnish with parsley.
Notes
Risotto is ready when you can run your wooden spoon through it and it fills the space back up slowly, sort of like wave on a seashore.