Preheat oven to 325°F.
Finely chop reserved mushroom stems. Set aside.
Place butter in a large skillet. Place over medium heat.
When butter has melted and is hot, but not browned, add onion, pepperoni, green pepper, garlic and chopped mushroom stems. Cook until tender, but not browned.
Add crackers, Parmesan, parsley, salt, oregano and a dash of pepper. Mix well.
Remove from heat. Allow to cool slightly.
Spoon mixture into mushroom caps, heaping tops.
In a shallow baking pan, add enough chicken broth to cover the bottom of pan up to 1/4-inch.
Carefully place stuffed mushrooms in pan.
Place in preheated oven and bake, uncovered, about 25 minutes until heated thoroughly.
Serve hot from cooking pan. Or serve as Carrabba's does - Spoon hot Carrabba's Italian Grill Tomato Cream Sauce into individual serving dishes to cover the bottom to about 1/4 inches. Place 4 or more mushrooms upright into each dish. Serve hot.