Preheat the oven and prepare the potatoes

• Preheat the oven to 180 °C.
• Peel the potatoes and slice them thinly, ideally with a mandoline.
• Grease the baking dish with butter and rub it with a garlic clove.

Warm the cream mixture

• Pour the milk and cream into a saucepan.
• Add the minced garlic, grated nutmeg, salt and pepper.
• Warm over low heat without boiling.

Assemble the gratin

• Layer the potato slices in the baking dish.
• Pour the warm cream mixture over the potatoes.
• Scatter the grated gruyère on top.

Bake the gratin

• Bake until the potatoes are tender and the top is golden.
• Let it rest for a few minutes before serving.

Cook the chicken

• Season the chicken with salt and pepper.
• Sear in a hot pan with olive oil and a little butter until golden and cooked through.

Make the tomato and parsley salad

• Combine the tomato wedges, sliced red onion and chopped parsley in a bowl.
• Dress with olive oil, lemon juice, salt and pepper and toss gently.

Serve

• Serve the chicken with a portion of potato gratin.
• Add the tomato and parsley salad on the side.