01 -
Preheat oven to 190°C. Brush the inside of a 25 centimetre cast-iron skillet with olive oil and set aside.
02 -
Peel all potatoes and, using a mandolin or sharp vegetable slicer, cut into very thin, uniform slices.
03 -
In a large bowl, gently toss sliced potatoes with salt, pepper, garlic powder, thyme, sage, parsley, rosemary, most of the grated cheese (reserve a small amount for topping), and chopped onion until evenly coated. Take care not to break the potato slices.
04 -
Working with a small handful at a time, neatly arrange the coated potato slices upright in the prepared skillet or a 2-litre baking dish. Sprinkle the top with the reserved cheese.
05 -
Pour the milk and chicken broth evenly over the layered potatoes.
06 -
Cover the pan tightly with foil, sealing the edges. Bake for 50 minutes.
07 -
Remove the foil and continue to bake for an additional 15 to 20 minutes, or until the potatoes are tender and the top is golden brown. Test for doneness by inserting a knife through the layers.
08 -
Allow to cool briefly before serving. Present hot for optimal texture and flavour.