Reuben Bake: A Warm, Cheesy, and Crispy Casserole Inspired by the Classic Reuben Sandwich

Preheat the Oven: Preheat your oven to 375°F (190°C). Grease a 9×13-inch baking dish.
Prepare the Bread: Heat a large skillet over medium heat and melt the butter. Add the cubed rye bread and toast until golden and crispy, about 5-7 minutes. Remove from the heat and set aside.
Cook the Onions: In the same skillet, add the chopped onion and sauté for 2-3 minutes until softened.
Assemble the Casserole: In the prepared baking dish, layer half of the toasted rye bread cubes. Top with half of the corned beef, half of the Swiss cheese, half of the sauerkraut, and half of the sautéed onions. Repeat the layers with the remaining bread, corned beef, cheese, sauerkraut, and onions.
Make the Dressing: In a small bowl, combine the Russian or Thousand Island dressing, sour cream, and Dijon mustard. Pour the dressing evenly over the casserole.
Bake: Cover the baking dish with foil and bake for 25 minutes. Remove the foil and bake for an additional 10-15 minutes until the cheese is melted, bubbly, and golden brown on top.
Serve and Garnish: Let the casserole cool for a few minutes before slicing. Garnish with fresh parsley, if desired.
Serving and Storage Tips