Preheat oven to 375 degrees F.
Cut the Kasier rolls in half. Place the bottom halves, cut side up, on a baking sheet. Spread 1 teaspoon of the Russian dressing over cut side of each bottom of roll. Slice 4 equal pieces of corned beef; place 1 slice on top of dressing on each roll. Top with the sauerkraut and the shredded cheese, dividing equally.
Bake the sandwich halves in the preheated 375 degree F oven for 10 to 15 minutes or until the cheese is melted. For the last 5 minutes of baking, place the tops of the rolls, cut side up, on a baking sheet in the oven to toast.
Garnish the sandwiches with the red onion rings and lettuce leaves; top each sandwich with a toasted roll half. Makes 4 servings.