1️⃣ THE FIRST TASK: Let's prepare the layered potato brick!

Prepare a bowl of seasoned cream: Get a bowl (as pictured), and pour the cream and milk. Season the cream with salt, and a little fresh cracked pepper.

I used 3 or 4 measured teaspoons of flaked salt. It'll end up tasting like a cross between sea water and cream.

Peel the potatoes. Then get your mandolin, put it over the bowl of cream, and start slicing into the bowl.

Choose a very thin setting on your mandolin. You want slices that are credit card thickness. You can almost see your finger through them when you hold them up.

Ensure the slices are submerged in the cream – this adds flavour, and prevents the slices from oxidising while you're waiting.

(Here I used a Joseph Joseph mandolin, on its thinnest setting – number 1.)

Prepare a loaf pan: Preferably use a cast iron loaf pan with a lid, if you have one (I don't). Grease the pan (butter is fine), then add greaseproof paper, and grease the inside of the paper too.

We're going to be stacking many layers of sliced potato in here. Make sure the greaseproof paper is big enough that, once you're done layering (see later steps), you can close the paper on top of the brick and cover the top.

The loaf pan I've used here is 24cm x 15cm x 6.5cm, measured at the top.

Let's start layering up!

Remove a slice from the bowl, shake off the excess cream, and layer it into the bread pan.

Every two or three layers, add a sprinkle of salt, some pepper, a grating of parmesan cheese, and a light sprinkling of herbs (parsley, thyme, or sage, or a mix of all of them).

The whole layering process can take up to an hour. Prepare a video, podcast, or some music. Or simply treat it all as a silent meditation through cooking.

Keep layering until you have a good depth; e.g., up to just below the top of the loaf pan. Or until you've run out of slices.

Every few layers, try to level the brick with your hand.

Ideally the result should be at least 2-inches deep.

When you're getting toward the end, preheat an oven to 170 degrees C (fan) ready for the next steps.

Once done layering, try to level the brick. Use the back of your hand to evenly press down. Then, close the greaseproof paper on top. Cover the pan tightly in foil. If you have a lid, put it on top of the foil for an even tighter seal.

Bake in the oven for approx 2 hours at 170 degrees (fan, celsius).

Once baked, remove the pan from the oven. 2 hours should be the right duration, but you can also check it's done if the potato is soft. Do a knife test (does the knife go in easily, and come out clean?).

Let the brick cool to room temperature (keep it covered with the foil).

Once it's cool enough (and as soon as you reasonably can), cover with cling film and then recover with foil. Put something heavy and weighted on top, to compress the whole brick down. Another tin with weights or heavy cans on top works.

2️⃣ THE SECOND TASK: It's frying time!

Remove the pan from the fridge, and take the brick out of the pan. You might be able to pull it up with the greaseproof paper. However, if the brick's squished in tight, you might also need to carefully separate the brick from the sides using a thin spatula. Slide the spatula between the greaseproof paper and the sides of the pan. Try not to damage the layers.

Tip: Don't leave the brick out of the fridge too long, as the layers will lose some integrity and allow it to fall apart when frying.

Trim the two ends of the brick. Then chop into rectangular blocks, each of maximum 3cm in width. Then trim the ends of the blocks. The result is some crisp blocks.

Heat a pan up to a medium-high temperature. Put some oil in there. Enough that the bottom of the potato blocks will sit in a few millimetres of oil. (Try a small-diameter pan if you want to save on oil.)

Add two or three sprigs of fresh thyme, for extra flavour.

(Some people user butter instead, but be sure that it doesn't burn!)

You'll now fry the block on each of its six sides. I recommend doing the end bits first (so the block sits vertically). Then the top and bottom. Then finally the sides. Have a look at the photos in then next steps...

While you're frying, baste the block by spooning the oil.

You want to get each side golden brown, with a hint of crispy (see photos). You want to get some crunch when you bite into these.

This typically takes approx 10 mins for all sides (1.5 to 2 mins per side).

Each end side first. Then bottom and top. Finally, the largest sides.

Serve the gratin blocks as you like. A little grated parmesan is nice.

Here's some more photos of the finished result.