Preheat the oven to 190 °C.

Add the balsamic and the honey to a small saucepan over a medium heat and allow to reduce until thick and syrupy.

Slice the potatoes on a mandolin if you have one to ensure thin, even slices.

Pour 3 tablespoons of butter into a cast iron skillet over medium heat. Start layering your potatoes in circles into the skillet until you have a few layers down. Season with salt, pepper, and thyme in between.

Working quickly, add more potato slices as before and repeat the process and add a drizzle of the balsamic and honey reduction.

Repeat once more and then pour in the remaining 3 tablespoons of melted butter. Repeat with remaining potatoes, balsamic, salt, pepper and thyme until done.

Press down firmly with a plate and bake for 30 minutes. Carefully remove from oven and press once again. Return to the oven and bake a further 25 minutes.

Cool completely after removing from the oven, run a knife around the edges and flip out onto a serving plate, or alternatively serve in your cast iron dish.