Tian is a French term for a shallow, earthernware dish, as well as the food that is cooked in it. A tian is a type of gratin, typically vegetables baked in an earthenware dish.
1.Preheat oven to 200°C/400°F.
2.Using a mandoline, slice zucchini on the diagonal into 1cm (½in) thick ovals; place in a large bowl. Cut eggplant and sweet potatoes into 2mm thick rounds. Add to bowl with 2 tablespoons of the oil; season well. Toss to combine.
3.Reserve ¼ cup of the pesto. Pulse chickpeas, remaining pesto and parmesan in a small food processor until very coarsely combined. Spoon three-quarters of the chickpea mixture over the base of a 3-litre (12-cup), 22cm x 30cm (8¾ in x 12in) shallow ovenproof dish.
4.Arrange vegetables in overlapping layers over chickpea mixture. Cover dish with foil; bake for 50 minutes or until vegetables are tender. Place tomatoes in the gaps; sprinkle with remaining chickpea mixture and remaining oil. Bake, uncovered, for a further 15 minutes or until golden and vegetables are cooked through.
5.Top tian with mozzarella, drizzle with remaining pesto and scatter with basil. Season to taste.
You can use purple or all white sweet potato instead of orange, if preferred.
Chickpea mixture can be made a day ahead and refrigerated. Recipe is best made close to serving.
If you’re entertaining vegetarians or vegans this Christmas, our recipe, which is also gluten-free, is a tasty option as a centrepiece main course. Brimming with punchy Mediterranean flavours, it’s bound to be a real showstopper.