Baked Mushrooms Appetizer

I had these mushrooms last night at a get together and they were awesome! They make a great appetizer.

Mushrooms

2 lb. mushrooms, stemmed
melt 3 sticks of butter,
add
2 t. onion finely chopped
1 clove garlic
1/2 t. salt
3/4 t. rosemary
3/4 t. worcestershire sauce
1/2 t. pepper

Bake 40 minutes uncovered at 325* F. Cut french baguette and serve with toothpicks.