Separate the cabbage leaves and cut out the thick ribs. Bring a saucepan of salted water to the boil, add the leaves and simmer 10-15 minutes. Drain.
Crumble the bread and soak in milk. Meanwhile, heat 2 tablespoon oil in a saucepan and saute the onion until translucent. Add the parsley and stir. Squeeze the bread dry and add to the onions.
Mix the onions with the egg and salt and pepper. Divide the filling between the twelve largest cabbage leaves and roll up, tucking in the ends.
Place the cabbage rolls in a saucepan, add the stock and tomato puree and bring to a simmer. Cover and cook 30 minutes.