Spread the Russian dressing on the bread. Layer the pastrami, sauerkraut, and cheese on one slice and cover with the other slice, dressing side down. Melt half of the butter in a skillet and brown the sandwich until the bottom is golden. Add the remaining butter, flip the sandwich and cook until brown and the cheese has melted. Cut in half and serve or eat at once, with dill pickles and coleslaw. Makes 1 sandwich