Blend the different flour types in a bowl together with the sugar and dry yeast (unless the yeast has to be dissolved in water, in which case we recommend you follow directions on the package). Slowly add the milk and the melted butter, then start to knead.
This can be done by hand or using a machine with dough hooks.
As soon as the flour is completely blended into the dough, add the salt and knead about another 10 minutes until the dough is smooth and uniform.
Cover the bowl with foil and let it rise for 12 hours in a refrigerator.
Take the dough out of the fridge and let it rest another hour at room temperature.
Using a scale separate the dough into 30 g portions.
Fold the outer edges of each dough portion to create the shape of a roll.
Place the rolls on a cookie sheet covered with parchment paper and let them rise for an hour. Whisk together an egg with milk in a bowl, then coat each roll with this. Sprinkle with the seeds. Bake in a preheated regular oven at 200°C (180°C convection) for 12-14 minutes. Take the rolls out of the oven when they‘re golden brown on top.
Completely cool on a grill rack.
According to taste, serve with cold cuts and cheese slices on top.