Put the flour in a large bowl. Whisk in the salt, fresh yeast and onion.
Mix the water with the yoghurt, then add the egg and honey, whisking until the honey has dissolved.
Add the liquid ingredients to the dry ingredients, mixing thoroughly to form a soft dough. Knead lightly until the dough is smooth, then return to the bowl, cover with a damp cloth or cling film and leave to rise overnight or until doubled in size.
Preheat the oven to its highest setting and put two baking trays in the oven.
Divide the dough into 12 equal pieces. Shape into balls, then roll into thin rounds. Put the rounds on the baking trays, in batches if necessary, and cook for about 3 minutes, until puffed up and turning a light brown on the underside.
Remove the breads from the oven and brush with the melted butter. Sprinkle with the dill and caraway seeds and leave to cool.