Preheat your oven to 180°C / 350-375°F / Gas Mark 4-5
Spray a 26cm round or approx same size baking dish with cooking oil and set aside
Use a vegetable peeler to peel each of the potatoes
Use a mandolin to thinly slice the potatoes
Transfer the sliced potatoes to a mixing bowl. Add the dried onion, thyme, salt and pepper. use a spoon to stir to combine.
Pour 1/2 of the cheese into the potatoes and stir again to combine
Pour the cream into the seasoned potatoes and use the spoon to (gently) stir the cream through the potatoes till combined
Transfer the creamy potato mix into the baking dish and cover with foil
Place the skillet or baking dish onto the middle rack of the oven and bake (covered) for 30 mins.
Use oven mits to remove the skillet from the oven, discard the foil, then sprinkle the remaining cheese on top.
Return the potatoes to the oven for another 10 mins, till the cheese is melted and a light golden brown
Garnish with chopped parsley