1. Cut off the top of the rolls and remove the inside. Brush with melted butter. Place them on a baking dish. Preheat oven to 350º and bake rolls for 20 minutes or until browned.
2. Purée the avocados. Add the lemon juice, salt and scallions. Cover and refrigerate for 1 hour.
3. Pat dry the oysters and dredge in bread crumbs. Fry oysters in deep hot oil 1-2 minutes, or until browned.
4. Fill the rolls with the avocado purée and place the fried oysters on top. Serve cold.