Pour the stock into a medium-sized saucepan and bring to a simmer over a low-medium heat.
Meanwhile, add a generous drizzle of olive oil into a large non-stick pan set over a medium-high heat. Add the cherry tomatoes and cook for about 5 minutes, stirring occasionally, or until nicely charred and blistered, but not completely falling apart. Tip into a bowl and set aside.
Add another generous drizzle of olive oil to the pan, reduce the heat to low-medium and add the finely chopped onion. Cook for about 8-10 minutes, stirring occasionally, or until starting to soften.
Stir in the garlic and tomato purée and cook for about 2 minutes, stirring, or until fragrant. Add a splash of water if it starts to stick.
Add the arborio rice and cook for a few minutes, stirring until the grains are lightly toasted and translucent.
Pour in a ladleful of the simmering stock and stir until almost all of it has been absorbed. Keep the heat low - you don’t want to rush this stage. Gradually repeat this process until all of the remaining stock has been absorbed and the rice is al dente. This should take around 18-20 minutes.
Meanwhile, for the prawns: melt the butter and olive oil in a large non-stick frying pan placed over medium-high heat. Add the prawns, followed by the garlic and smoked paprika. Season with salt and freshly ground black pepper. Sauté for about 2-3 minutes, stirring occasionally, or until the prawns are blushing pink and just cooked. Take care not to overcook them or they will turn rubbery. Remove from the heat, squeeze over lemon juice, to taste and stir through the chopped parsley.
Once the rice is cooked, stir the reserved jammy tomatoes into the risotto. Season with salt and freshly ground black pepper, to taste. Add lemon zest, to taste (I use about ½ a lemon) plus lemon juice, if desired.
Stir in a knob of butter, followed by the mascarpone, until combined. Sprinkle in most of the basil leaves and fold through. Taste and adjust the seasoning, as necessary.
To serve: spoon the risotto onto serving plates. Top with the prawns and a tsp of mascarpone. Garnish with fresh basil leaves. Season with freshly ground black pepper. Squeeze over a little extra lemon juice and drizzle with extra virgin olive oil. Enjoy!