Preheat the oven to 180 degrees C.
Cut the potatoes into scallops a few mm thick by using a food porcessor which has a slicing option, or use a mandoline or sharp knife - please watch your hands! If using a knife, it's very hard to get the slices thin so please prepare the potatoes by blanching them in a pan of hot bubbling water for a few minutes after slicing as this will soften them and result in a faster cooking time in the oven. Just run them under cold water in a sieve to cool them down for ease of arranging them in the next step.
Next, arrange the scallops, starting from the outer edge and working your way around the dish and towards the centre. Use the image as an example. Or create your own design ;)
Once all of the filling has been covered with the potaoes, brush the whole surface with a little oil to encourage them to crisp while cooking.
Place the dish into the oven and bake for at 30-40mins at 180 degrees C. The time difference completely depends upon the thickness of the potato slices. The thicker the potatoes, the longer cooking time they will require. If the potatoes are cooked but not crisp, you can always finish it off under the grill for a few minutes, if you oven proof dish allows for that - some glass oven dishes state that they are not to be placed under direct heat such as a grill so refer to the manufacturers instructions if unsure!
Serve with some steamed greens or green leaves.