Add 1 tbsp olive oil to a large non-stick deep frying pan set over a medium heat. Add the sliced courgette and fry for a few minutes, stirring occasionally, until golden brown and cooked through. Tip into a bowl and set aside.
Add the remaining oil and the butter to the pan. Once the butter has melted, add the onion and fry for about 7 minutes, stirring occasionally, until starting to soften. Add the garlic and cook for 30 seconds before stirring in the rice. Cook for 1-2 minutes, stirring often, coating in the buttery onions and garlic. Add the grated courgette and give it a good stir.
Gradually add a ladle of the hot stock to the rice allowing it to bubble over a medium heat whilst stirring constantly. Once almost all of the stock has been absorbed, add another ladle and continue stirring. Repeat this process until the rice is cooked and you have a lovely creamy risotto - this should take between 18-22 minutes.
Add the Parmesan, mascarpone and fried courgette rounds. Stir well to combine. Season to taste.
Scoop onto plates and top with the mozzarella, basil and chives. Squeeze over the lemon juice and drizzle with extra virgin olive oil. Enjoy!