Cut up onions and layer in large enough pan to hold ribs covered.
Lay ribs over onions and cover with beer.
Tightly cover pan with lid or foil and cook for 3 hrs @ 300 degrees.
While ribs are cooking mix next 4 ingredients in pan on stovetop, heating gently until ingredients are well combined -- sauce will be thin -- don't worry.
Remove ribs from beer and onions and either bake broil or grill basting often with barbq sauce.