Ham cheese croissants

Ingredients for 4 servings:
Dough:
250 g flour
125 g quark (40%)
50 ml vegetable oil
50 ml milk
3 tsp baking powder (leveled, 10g)
1 egg white
0.5 tsp salt (leveled)
filling
200 g cooked turkey ham (slices)
300 g cheese (slices, Gouda, young)
1 egg yolk
1 tablespoon milk
1 pinch of pepper (ground)
possibly sesame
Preparation: