In a wok braise onion till golden brown colour, add tomatoes and spices braise till forms a paste add sauces and veggies cook little should be saucy. Keep off flame.
In a casserole pour veggie mixture, then make a layer of potatoes poke with fork all over then sprinkle dried herbs and put butter (or grated parmesan cheese) all over.
Bake in oven on 230C, remove from oven and serve hot.