Clean mushrooms and remove caps from stems - reserve stems

In food processor, finely chop stems and onion

Heat butter over low heat and add chopped stems and onion - cook about 5 minutes while stirring gently

Add parmesan cheese and bread crumbs and toss gently

Remove mixture to bowl using slotted spoon to allow butter to drain back into skillet

Add cream to chopped mixture, stir and set aside

Place caps in skillet and cook slowly, turning occasionally and moving gently with a spoon - add more butter when necessary - cook until caps are browned and tender

Remove caps and fill with bread/cheese mixture

Top with bacon and broil about 3 inches from broiler for 4 minutes or until bacon is done

Serve immediately