Olive Garden Stuffed Mushrooms

8 to 12 large mushroom caps
1 (6 oz.) can clams drained, finely minced (save 1/4C clam juice for stuffing
1 green onion chopped finely, about 1 Tbsp.
1 egg beaten
1/2 tsp. minced garlic (or more to taste)
1/8 tsp. salt
1/3 to 1/2 C Italian flavored bread crumbs
1 tsp. oregano
1 Tbsp. melted butter, cooled
2 Tbsp. each grated Parmesan & Romano cheese
2 Tbsp. grated Mozzarella (for stuffing)
1/4 C. grated Mozzarella (for garnish)
1/4 C. melted butter

Preheat oven to 350 degrees. Wash and remove stems from mushrooms, pat dry. In mixing bowl, place clams, onions, salt, garlic, butter and oregano. Mix well. Add egg, clam juice and enough bread crumbs to bind mixture without making it too dry. Place slightly mounded mixture into each cap and place in lightly oiled baking dish. Drizzle butter over mushrooms. Cover with foil and bake for 35-40 min. Remove cover and sprinkle freshly grated mozzarella cheese on top and return to oven just until cheese melts.