Preheat and Prepare: Preheat your oven to 200°C (180°C fan). Generously grease a 12-cup standard muffin tin with butter or a neutral oil spray. Don’t be shy here; a good coating prevents sticking and helps the bottoms crisp up.

Slice the Potatoes: Wash and peel the potatoes. Using a mandoline slicer or a very sharp knife, slice the potatoes into paper-thin rounds, about 1-2mm thick. Place the slices into a large mixing bowl.

Create the Flavour Mixture: In a separate, smaller bowl, combine the melted butter, grated Parmesan, garlic powder, onion powder, chopped thyme, sea salt, and black pepper. Stir everything together until it's well combined.

Coat the Potatoes: Pour the butter and Parmesan mixture over the sliced potatoes in the large bowl. Use your hands to gently toss and separate the slices, ensuring every single piece is coated. This is the secret to flavour in every layer. What works best for me is getting right in there to make sure no slices are stuck together.

Stack Them High: Begin stacking the coated potato slices into the prepared muffin tin cups. Pack them in tightly, pressing down gently as you go, until each cup is filled just above the rim. The potatoes will shrink a bit as they cook.

First Bake (The Steam): Drizzle any remaining butter mixture from the bowl over the tops of the stacks. Cover the muffin tin loosely with aluminium foil. Bake for 30 minutes. The foil traps steam, which cooks the inside of the stacks until they are tender.

Second Bake (The Crisp): After 30 minutes, carefully remove the foil. Return the muffin tin to the oven and bake uncovered for another 20-25 minutes, or until the tops and edges are deep golden brown and wonderfully crispy.

Rest and Serve: Let the potato stacks cool in the tin for about 5 minutes. This helps them set and makes them easier to remove. Run a small knife or offset spatula around the edge of each stack to loosen, then carefully lift them out. Serve immediately while hot and crispy.