Heat oven 300.

Line large cookie sheet with heavy duty foil.

Scatter onions on foil to make a "bed" for the ribs.

Place ribs on onions and season with salt, pepper or rub.

Pour beer on top.

Cover tightly with foil.

Place in oven for 2. 5 hours.

Let rest or place on grill for 10 minutes to give the ribs a crust.

If making ahead, let ribs rest-- refrigerate until ready to grill and eat.