Rinse prawns under cold running water. Remove the prawn head and tail, then peel off the shell and legs. To de-vein the prawn, use a sharp knife to cut a small line that runs down the length of the prawn’s back. Use the tip of the knife to pull out the intestinal tract and discard.
Place 2 tablespoons (40ml) of the olive oil in a small frying pan over medium heat. Add the garlic and cook without browning for 1-2 minutes. Add the prawns and cook for until the prawns have just changed in colour. Use a slotted spoon to transfer the prawns to a plate. Discard garlic clove.
Melt half of the butter and the remaining 1 tablespoon of olive oil in a large, deep-frying pan (or stockpot) over medium heat. Stir in the onion and cook until softened. Add the zucchini (courgette). Cook, stirring, for a few minutes until the zucchini has softened. Season with sea salt to taste. Stir in the rice and after 2 minutes, pour in the white wine. Cook, stirring, until all the liquid has been absorbed.
Add a ladleful of the hot stock, stirring constantly. When the stock has been absorbed, stir in another ladleful. Continue to add ladlefuls of stock, stirring and allowing each ladleful to be absorbed before adding the next until the rice is ‘al dente’ (approximately 15 minutes). Stir the prawns into the risotto over the heat, stirring constantly for 1 minute.
Remove the frying pan (or stockpot) from the heat. Stir in the remaining butter and Parmigiano Reggiano – buon appetito.