Potato, pumpkin and turnip gratin with chat masala

Chat masala is a perfect spice companion for the earthy flavours of root vegetables. If you don’t want to go to the bother of making individual gratins (for which you need stainless steel rings, available from good kitchen suppliers), you can easily make one large one in a baking dish. Just overlap the sliced vegetables, brushing the layers with the spice paste as you go, and adjust the cooking time — a 24 cm square gratin will need about 45 minutes’ cooking at 190°C.