Set potatoes in a casserole. Cover with cold water. Salt and bring to a boil. Cover and cook for 20 to 25 minutes at low heat until potatoes are cooked al dente. Drain and cool down.
Melt butter in a pan over medium heat. Fry onion or sliced leeks with bacon for 2 to 3 minutes. Season.
Finely slice potatoes.
Butter a square baking plate of 20 cm (8 inches) and at least 6.5 cm (2 1/2 inches) deep. Spread about a third of the potato slices on the plate, then cover with onions or sliced leeks and bacon. Repeat this step once again. Cover with a last layer of potatoes. Pour cream. Cover with cheese, then pour white wine.
Oven bake for 20 to 25 minutes, until potatoes are cooked.
Did you know that...
Leeks are rich in minerals (iron, potassium, phosphorus, magnesium, copper and calcium).