1 1/2 quarts oil 2 cups coleslaw 1 tablespoon water 1/2 cup thinly sliced onion 4 ounces chopped corned beef 1/2 teaspoon black pepper 1/4 teaspoon salt 1 cup diced cooked potatoes 1 cup Monterey Jack cheese, divided 8 (7 inch square) egg roll wrappe