Slightly undercook the gluten free pasta, then drain, reserving a ladleful of cooking water. Rinse the pasta with cold water to cool. Drain again, toss in a little oil to stop it sticking together and set aside while you get the rest of the bake ready.
Fry the zucchni/courgettes in oil for about 10 mins to drive off most of the liquid; they should reduce down a lot. Add the garlic oil to the pan, cook for 2 mins more, then season really well and add to the pasta. Stir in most of the lactose free cream, lemon juice and half the Parmesan with seasoning, then tip into an ovenproof dish. Dollop the rest of the lactose free cream over the top.
Heat oven to 180C/160C fan/gas 4. Whizz nearly all of the basil, remaining cheese, gluten free breadbread and pine nuts together to make pesto crumbs, then scatter all over the top. Finish with a few more pine nuts. Bake for 20 mins until the topping is crisp and bubbling at the edges. Serve with a few more basil leaves scattered over.