1
Preheat the oven to 200°C/180°C fan/400°CF/Gas 6. Cook the pasta in boiling salted water for 10 minutes until not quite cooked. Drain and set aside.
2
Meanwhile, in a small food processor, blitz 200g peas with the garlic, basil, mint, pine nuts, the mascarpone and Parmesan. Loosen it up with a little olive oil and season with salt and pepper.
3
Melt the butter in a pan, gradually add the flour and cook for 2 minutes, then gradually add the vegetable stock until you have a smooth, thick sauce. Add the pesto and stir until smooth. Season to taste.
4
Stir the sauce through the pasta, add peas and tip into an ovenproof dish. Scatter with the rest of the Parmesan and the grated mozzarella and bake for 20-25 minutes until bubbling and golden.