Get a head start on party prep when you refrigerate assembled sandwiches up to 8 hours. Pour the butter mixture over just before baking.
Preheat oven to 350°F. Line a 13x9-inch baking pan with foil. Coat foil with nonstick cooking spray. Arrange roll bottoms in prepared pan.
Combine pickled mixed vegetables, peppers, olives, and olive oil. Layer roll bottoms with turkey, vegetable mixture, and cheese. Add roll tops to sandwiches. Stir together butter, garlic, and Italian seasoning; drizzle over rolls. Cover with foil.
Bake 15 minutes. Uncover; bake 10 to 15 minutes more or until cheese is melted and rolls are lightly browned. Makes 12 pan-wiches.
Prepare sandwiches through Step 2, except do not drizzle with butter. Cover and chill overnight. Uncover; drizzle with butter and cover with foil. Bake as directed in Step 3.