Preheat and Prepare: First things first, preheat your oven to 200°C (180°C fan). Line a sturdy baking tray with baking parchment.

Wash and Dry the Potatoes: Give the potatoes a good scrub under cold water to remove any dirt. It's very important to pat them completely dry with a tea towel or kitchen paper afterwards. A dry surface is key to getting crispy skin.

Slice the Potatoes: Place a potato between your two chopsticks or wooden spoon handles. Using a sharp knife, make thin slices across the potato, about 3-4mm apart. The chopsticks will stop your knife from cutting all the way through. Repeat with all the potatoes.

Make the Garlic-Thyme Butter: In a small saucepan, gently melt the butter with the olive oil over a low heat. Once melted, stir in the minced garlic and the leaves from the thyme sprigs. Let it infuse for a minute, but don't let the garlic burn.

First Baste: Place the sliced potatoes on your prepared baking tray. Brush about half of the garlic butter mixture all over the potatoes, trying to get a little between the slices. Sprinkle generously with sea salt flakes and black pepper. What works best for me is using a silicone pastry brush to gently nudge the slices apart.

Initial Bake: Place the tray in the preheated oven and bake for 30 minutes. At this point, the slices will have started to separate and fan out.

Second Baste: Carefully remove the tray from the oven. Now, brush the remaining garlic butter over the potatoes. This time, you can be more thorough, ensuring the butter drips down into all the gaps that have opened up. This step is crucial for flavour and crispiness.

Final Bake: Return the potatoes to the oven and bake for another 30-40 minutes, or until they are deep golden brown, the edges are wonderfully crispy, and a skewer inserted into the centre goes through with no resistance.

Serve Immediately: Let them rest for a minute before serving. Garnish with a few extra fresh thyme leaves and another sprinkle of sea salt flakes if you like.