Saute onion in a bit of oil until just translucent. Add hamburger and saute until no longer pink. Season with salt and pepper. Drain away the grease, and return to the pan. Cover the mixture with the shredded cabbage and cook until the cabbage is done. Stir occasionally. This could take about 45 minutes or so.
Using an egg-dough recipe, roll small balls of dough thin to make a 5×5 square. Put about 1/2 cup of cabbage mixture in center of square and seal closed. (See note below). Place seal side down on a parchment lined baking sheet (or a lightly greased sheet). Allow these to sit, covered lightly with a tea towel, for about 20 minutes – so the dough can rise for the second time.
Bake 20-25 minutes at 350 or until lightly golden brown.
A side note: Use a slotted spoon or similar when filling the dough to allow the cabbage/hamburger mix to be dry’ish. You don’t want these “juicy” or the bottom of the roll will be doughy and wet and not cook properly.