Preheat the oven to 200ºC.
Heat oil in a large oven proof baking dish over medium heat. Add fennel and garlic and cook stirring for 3-4 minutes or until tender.
Add the rice, stock and mix to combine. Cover with a tight fitting lid or aluminium foil and bake for 35 minutes.
Peel the prawns, removing the head and vein.
Remove risotto from the oven, stir in the prawns, cover and cook for a further 5-7 minutes or until the rice is al dente and prawns are cooked.
Stir through the butter, parmesan and lemon zest, season with salt and pepper.
Top with extra parmesan, basil and serve with a rocket salad.