Jersey Royal Potato Gratin with Leeks, Gruyere and Thyme

Preheat oven to 180°C (160°C Fan/ Gas Mark 4). Grease a 9x13 inch baking dish with butter.

Thinly slice the Jersey Royal potatoes using a mandoline or a sharp knife. Aim for slices about 2-3mm thick. Place in a bowl of cold water to prevent browning while you prepare the leeks.

Melt the butter in a large saucepan over medium heat. Add the sliced leeks and cook gently for 5-7 minutes, until softened but not browned. Add the minced garlic and cook for another minute until fragrant.

Drain the potatoes and add them to the saucepan with the leeks and garlic. Stir to combine.

Pour in the Jersey milk and double cream. Season with salt, pepper, and a pinch of grated nutmeg. Bring to a gentle simmer, stirring occasionally, and cook for 5 minutes, allowing the potatoes to soften slightly and the sauce to thicken a little.

Remove the saucepan from the heat and stir in half of the grated Gruyere cheese and half of the chopped fresh thyme.

Pour the potato mixture into the prepared baking dish. Spread evenly.

Sprinkle the remaining Gruyere cheese and thyme over the top of the gratin.

Bake in the preheated oven for 30-40 minutes, or until the potatoes are tender and the top is golden brown and bubbly.

Let the gratin rest for 10 minutes before serving.