Preheat the oven to 350°F (180°C).

Butter a pie dish. Peel the potatoes, rinse them, and slice them very thinly using a mandoline or a knife.

Wash the zucchini and slice it into thin rounds.

In a bowl, beat the eggs, add salt and pepper, then add the sour cream and milk.

Spread the sliced vegetables in the dish. Pour the beaten eggs over the top and bake for 30 minutes.

Remove the quiche from the oven and let it cool for 5 minutes before serving.