200°C Fan Oven.
Boil the potatoes until tender in salted water.
Brush a 23 cm diameter springform pan with melted butter. Place the boiled potatoes in the pan and press them firmly into the bottom and up the sides to form a crust. Bake for 15 minutes.
Rinse and slice the leeks into thin rings. Pour boiling water over the leeks and let them sit for 3 minutes to blanch. Drain the water and pat the leeks dry with paper towels to remove excess moisture.
Fry the bacon cubes in a pan. Just before the bacon turns completely crispy, add the onions. Transfer everything onto a plate lined with paper towels to absorb the excess fat.
Whisk together eggs, crème fraîche, grated cheese, salt, and pepper.
Distribute the leeks and bacon/onion mixture over the potato crust and pour the egg mixture on top. Bake the tart for about 20 minutes.
Garnish with chives. Carefully remove the springform and serve the tart. Enjoy!
