Potato, Apple And Leek Gratin - cooking recipe

Ingredients

1 1/2 lbs waxy potatoes, peeled and sliced
8 oz leeks, halved lengthways and cut into 2\" pieces
11 oz red apples, cored
1-2 tsp lemon juice
4 sprigs thyme, stalks discarded
1 1/8 cups sour cream
1/2 cup cream
1 medium egg
3.5 oz Gruyere cheese, cubed (about 3/4 cup)
6 slices Parma ham

Preparation

Preheat oven to 400\u00b0F. Cook the sliced potatoes in boiling salted water for about 10 minutes, add the leeks for the last 2 minutes. Drain and set aside.
Slice the apples and drizzle with lemon juice. Then, combine apples in a greased baking dish with the potatoes, leeks and 2/3 of the thyme.
Whisk together the sour cream, cream and egg. Season with salt and pepper and pour over the potatoes. Distribute the cheese on top and bake for 30-40 minutes.
After 20 minutes of cooking, top with the parma ham and return to the oven. Serve with remaining thyme.