Place in large frying pan and cook until ready to turn.
Add butter and onion and cook until medium brown.
Add cut cabbage and add bay leaf,if using.
Add enough water to cover (1/4 cup at a time).
Cover and allow to steam, stirring often, and adding water as needed to help loosen brown bits in thr pan.
Cook 15-20 minutes (it will cook down quite a bit in volume.) Taste to check for desired tenderness, When almost done, add vinegar, stir, and heat an additional 5 minutes, Sprinkle with coarse black pepper just before serving, If desired.