500g strong plain flour, plus extra for dusting
7g dried yeast
320ml lukewarm water
a few dried breadcrumbs or a bit of semolina, for dusting
For the topping
80g Gruyère cheese, grated
250g crème fraiche
1 large red onion, thinly sliced
140g salami, cut into strips
Preheat the oven to 240°C/475°F/ Gas 9. Combine the flour, salt and yeast in a large bowl. Gradually add the water, mixing well with your hands to obtain a dough. If you find the dough too sticky, simply add a little more flour. Shape into a ball, cover with a cloth and leave to rest for 5 minutes. Knead the dough for about 10 minutes and split it in half. Sprinkle some flour on a clean kitchen cloth and place the pieces of dough on it. Cover with a slightly damp cloth and leave to rise for at least 30 minutes in a warm place.
Meanwhile combine the Gruyère and crème fraiche in a bowl, adding some salt and pepper to taste. Set aside.
Sprinkle some flour on a clean work surface and spread the dough into a circle about 30cm in diameter, making it as thin as possible (without tearing it), with the border slightly thicker. Repeat with the other dough ball. Sprinkle two flat baking trays with breadcrumbs or semolina and place the pizza bases on them.
Spread the crème fraiche mixture over each base. Top with the onions and salami. Bake in the hot oven for 10 minutes. Remove, sprinkle with marjoram and serve.