Make a battered dough from the above ingredients and refrigerate overnight. Don`t be surprised: the dough is very sticky immediately after preparation, but that is noticeable after the rest period.
For the filling, finely dice the ham, mix with the remaining ingredients and season with salt, a little caraway seeds and herbs. Preheat the oven to 210 ° C. Divide the dough into 4 equal portions, roll out each portion as thinly as possible into a round plate and cut into eighths with a dough wheel. Put about 1 teaspoon full of the filling on the broad side of the dough triangles, roll up the triangles from this side and bend them into croissants, press down the tips of the dough a little. Place the croissants on a baking tray lined with baking paper, brush with beaten egg yolk and sprinkle with caraway seeds (or sesame or poppy seeds) if you like. Bake until golden in about 15-18 minutes.