In a large saucepan, heat the olive oil and butter over medium heat. Add the chopped onion and cook until softened about 5 minutes. Stir in the minced garlic and cook for an additional minute

Add the Arborio rice to the pan and stir well to coat in the oil and butter. Cook for 1-2 minutes, stirring constantly, until the rice becomes slightly translucent around the edges

Pour in the white wine and cook, stirring, until most of the liquid has evaporated

Begin adding the warm stock one ladleful at a time, stirring frequently and allowing each addition to be absorbed before adding the next. Continue this process until the rice is creamy and tender, about 18-20 minutes

When the rice is nearly cooked, add the prawns to the pan. Cook for 3-4 minutes, stirring occasionally, until the prawns are pink and opaque

Stir in the Italian Volcano lemon juice, and grated Parmesan cheese. Season with sea salt and freshly ground black pepper to taste

Remove the pan from the heat and let the risotto sit for 1-2 minutes