Jersey Royal Potato and Gruyere Gratin

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 (about 1/8 inch thick). A mandoline can be helpful for this, but is not essential.

In a saucepan, melt the butter over medium heat. Add the minced garlic and cook for 1 minute until fragrant, being careful not to burn it.

Pour in the Jersey milk and bring to a simmer. Season with salt, pepper, and a pinch of nutmeg. Add the thyme leaves.

Add the sliced potatoes to the milk mixture and simmer gently for about 5 minutes, or until they are slightly softened. If using, add the asparagus pieces now and cook for another 2 minutes.

Remove from heat. Layer half of the potato mixture into the prepared baking dish, spreading them evenly.

Sprinkle half of the grated Gruyere cheese over the potato layer.

Repeat with the remaining potato mixture and Gruyere cheese.

Pour any remaining milk mixture from the saucepan evenly 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 5-10 minutes before serving.