Alsatian Tarte Flambée

Combine the flour and salt in a large bowl. Add the warm water and oil, mix to a shaggy dough, then knead on an unfloured surface for 5 minutes until smooth and supple. Divide into 2 equal balls and lightly oil the surface of each.

Cover the dough balls loosely with a clean cloth and leave to rest at room temperature for 30 minutes.

Meanwhile, melt the butter in a wide skillet over medium heat. Add the sliced onions with a pinch of salt and cook, stirring occasionally, for 12–15 minutes until softened and just beginning to turn golden at the edges — they should be translucent but not fully caramelised.

Remove from heat and cool completely.

Place a baking stone or heavy baking steel on the top rack of the oven and preheat to its maximum temperature (typically 270–300°C or 520–570°F) for at least 45 minutes.

While the oven heats, whisk the crème fraîche, fromage blanc, nutmeg, salt and white pepper together in a bowl until smooth and spreadable.

On a lightly floured surface, roll one dough ball into a very thin oval or rectangle, roughly 30×40cm — it should be almost translucent in places. Transfer to a sheet of baking parchment.

Spread half the crème fraîche mixture evenly over the dough, leaving a 1cm border. Scatter half the cooled onions evenly over the top, then distribute half the lardons across the surface.

Slide the tarte (still on the parchment) directly onto the hot stone and bake for 7–9 minutes until the edges are deeply charred in spots, the lardons are sizzling, crisped and cooked through (pork should reach at least 63°C — check with a meat thermometer if unsure), and the base is stiff and cracker-crisp when lifted at a corner.

Repeat the rolling and topping process with the second dough ball and remaining crème fraîche mixture, onions and lardons, and bake in the same way.

Remove from the oven, slice into rough rectangles, and serve immediately.