Beer/Garlic Baste for chicken Barbeque

From: (Kit Lueder)

1/2 cup margarine (or butter)
8 cloves garlic (or more!), chopped or pressed
1/2 cup onion (or more!), chopped
1 cup beer
2 Tbsp chopped parsley (or more!)
1 tsp coarsely ground black pepper

Melt the margarine in a sauce pan.  Add the garlic and onion,
and cook over a medium heat for about 5 minutes, till they are
soft but not browned.  Add the beer, stirring constantly, increase the heat,
and bring it to a boil.  Remove the pan from the heat.  Stir in the
parsley and pepper.  Frequently baste the sauce over the chicken
and spoon the onion/garlic on top of the chicken, while it cooks.