Flammekueche

Measure 90ml lukewarm water. Put the flour, yeast, sugar and salt in a food processor and mix, then gradually add most of the water and the oil. Add the remaining water as necessary to form a soft but not sticky dough. Remove the dough, knead briefly, cover with a large piece of baking parchment (which you will reuse in step 5), then set aside, or make ahead and chill for up to 24 hours.

Fry the bacon in a large frying pan, adding oil if necessary (streaky will need a drop, but bacon varies) for 3-4 minutes. When speckled brown, remove to a plate with a slotted spoon.

Add a little more oil to the pan if necessary and fry the onion and seasoning, covered, for about 7 minutes, until soft and juicy, then continue cooking for 7 minutes more, until brown at the edges.

Mix the crème fraîche, the finely grated nutmeg and plenty of seasoning. Preheat the oven to 230ºC, gas mark 8.

Put the dough on a large piece of floured baking parchment, sprinkle with flour, top with the reserved parchment and roll out as thinly as possible to a rectangle (with rounded edges) about 38x23cm. This requires patience, as the dough will want to spring back.

Spread the seasoned crème fraîche all over the base, allowing a 1cm border, then scatter over the onions and bacon. With the assistance of a baking sheet, slide the tart (still on its baking paper) directly onto the oven rack and bake for 9-12 minutes, rotating halfway, until the edges of the tart start to go brown (flambée) in places. Slice with a pizza cutter and serve.