Rinse mushrooms, pat dry, and trim stems. Set aside. Combine flour, bread crumbs, salt, and Italian seasoning. Set aside. Dip mushrooms into beaten egg, then into crumb mixture. Toss well to coat, then shake off excess crumbs. Heat oil in a deep-fat fryer to 375 degrees. Add mushrooms a few at a time, frying about 3 minutes or until golden. Remove mushrooms and place on paper towels to drain. Keep mushrooms warm as you repeat the process until all are used.