Tip the onion and fennel into a bowl, toss in the oil and microwave on High for 5 mins. Stir in the rice, pour over the stock, cover the bowl with a plate and continue to microwave on High for 10-15 mins more or until the rice is just on the verge of being cooked.
Throw in the seafood and peas, cover and continue to microwave on High for 2-3 mins until the rice is cooked. Stir in the parmesan and lemon juice and leave to stand for a moment while you mix the parsley with the lemon zest. Spoon the risotto into bowls and scatter over parsley and lemon zest.