For the pesto, peel and quarter the garlic. Wash the herbs and shake dry. Add the olive oil, herbs, garlic, pine nuts and lemon to a blender and blitz to a paste.
Grate the parmesan and add to the pesto; blitz briefly. Season with salt and pepper.
Peel and finely chop the onion and garlic. Rinse the prawns and pat dry.
Heat the olive oil and butter in a saucepan and fry the onion and garlic until softened. Add the risotto rice and cook, stirring, for 1-2 minutes.
Deglaze with the wine. Add enough stock to cover the rice grains. Continue stirring occasionally for 15-20 minutes, adding stock as needed.
Stir in the butter and season the risotto.
Fry the prawns in hot oil with the thyme until cooked through. Season with salt, pepper and lemon juice.
Swirl the pesto into the risotto and serve with the prawns on top of the risotto and sprinkle with pine nuts.