Slice 2 courgettes length ways and chargrill quickly under a hot grill, until marked but only part cooked. In a frying pan cook 1 thinly sliced small red onion and 1 clove of chopped garlic in ½ tsp of olive oil for 2 minutes. Add 200g (1/2 tin) of chopped tomatoes and simmer for 5 minutes on a medium heat. Pour the tomato sauce into an ovenproof dish and lay the sliced courgettes across the top. Roughly tear ½ a ball of mozzarella and scatter over the dish. Drizzle 1 tsp of pesto and sprinkle 2 tsp of breadcrumbs over everything. Bake in a hot oven Gas 6/180oc for 15 minutes.