Place ribs in shallow roasting pan, meaty side up.
On each piece place a slice of unpeeled lemon a thin slice of onions.
Roast in hot oven 450° F. 30 minutes.
Combine remaining ingredients; bring to boiling and pour over ribs.
Continue baking in moderate oven 350° F. until tender, about 2 hour.
Baste ribs with the sauce every 15 minutes.
If suace gets too thick, add more water.