Peel your potatoes and chop 4 of them into chunks. Add to a saucepan with cold water and the salt, then place on medium heat and bring to a boil. Boil the potatoes for 10 - 15 minutes or until they are fork tender and ready to mash.

Preheat the oven to 200C | 395F

Meanwhile, take your fifth potato and cut it in half lengthwise, then cut it into thin slices - we’ll use this one for the topping.

Soften the butter in the microwave (10-second bursts - softened but not melted) and mix in the minced garlic and parsley.

Drain your boiled potatoes and then add three-quarters of the butter, half the cheese, and the creme fraiche. Use a potato masher to mash the potatoes until smooth and fluffy, then season to taste.

Grease your oven-proof dish with some of the garlic butter, then scoop the mashed potatoes into it, pressing down gently so you have an even layer of potatoes.

Layer your potato slices on top of the mashed potatoes, slightly overlapping them as you would in a hotpot or au gratin.

Brush the potatoes with the remaining garlic butter, grated cheddar, and hard cheese.

Cover the dish with foil and bake for 45 minutes. Remove the foil and bake for a further 25 minutes, uncovered, until the potatoes on top are cooked through and the topping is golden brown and crispy.