Buttery & Savory Reuben Sliders Recipe. Ruben Sliders are buttery, savory appetizer-sized Reuben sandwiches, on Hawaiian roll dinner rolls, and filled with corned beef, sauerkraut, and Russian (or Thousand Island) dressing, and topped with melted butter. These hand-held Reuben Sliders are perfect party-sized appetizers for any type of party you are planning.