1. Preheat the oven to 445°F (230°C). Place a large round baking dish (approx. Ø 13 inches / 33cm) in the oven and allow to heat up with the oven.

2. Fry the diced bacon briefly in a pan without fat so it can brown slightly and get crisp. Remove from heat and set aside.

3. Peel the onion and cut it into thin rings. Set aside.

4. Mix sour cream with crème faîche and some lemon juice. Season with salt and pepper.

5. Spread the cream on top of the tortillas to cover them, edge to edge. Sprinkle evenly with the bacon onion rings. Place the first tortilla carefully in the hot baking pan and bake for 5-7 minutes. The edges of the tortilla should be crispy and the cream should bubble a bit. Remove from the oven. Season with more salt and pepper, if you like, and then sprinkle with some chopped chives. Serve immediately.

6. While enjoying the first tarte flambée, the next one can already be baked.