Bake waffle fries according to package instructions, set aside.
Add corned beef to 10” skillet and cook corned beef according to package directions. Break apart, set aside.
Place one half of prepared waffle fries on bottom of 9” x 13” rimmed baking sheet.
Top with one half of corned beef, half of sauerkraut and half of cheeses.
Repeat with a second layer on top.
Preheat oven broiler.
Place under broiler until cheese is melted and corned beef mixture is bubbling, about 5 to 7 minutes.
Remove from oven, sprinkle with sliced onions and drizzle with Thousand Island Dressing. Serve immediately.
