Melt the Butter: Heat a large soup pot or Dutch oven over medium heat. Add the butter and let it melt completely.
Cook Onions: Add the diced onion and sauté for 3-4 minutes until softened and translucent.
Add Garlic: Stir in the minced garlic and cook for an additional minute, stirring frequently to prevent burning.
Step 2: Create the Roux
Incorporate Flour: Sprinkle the flour over the sautéed onions and garlic. Stir constantly for 1-2 minutes to cook the flour and form a roux. This will help thicken the soup.
Add Broth: Gradually pour in the beef broth, whisking continuously to prevent lumps. Bring the mixture to a gentle boil.
Step 3: Build the Flavor Base
Add Corned Beef: Stir in the diced corned beef, letting it simmer for 5 minutes to infuse the broth with its savory flavor.
Incorporate Sauerkraut: Add the chopped sauerkraut and caraway seeds (if using). Simmer for another 5 minutes, allowing the tangy and slightly sour notes to meld with the soup.
Step 4: Add Dairy for Creaminess
Stir in Cream and Milk: Reduce the heat to low and slowly add the heavy cream and milk. Stir well to combine, ensuring the soup doesn’t boil, which could cause the dairy to curdle.
Season: Mix in the Dijon mustard and Worcestershire sauce. Taste and adjust with salt and black pepper as needed.
Step 5: Melt the Cheese
Incorporate Swiss Cheese: Gradually add the shredded Swiss cheese, one handful at a time, stirring until fully melted and smooth. This step gives the soup its signature creamy texture and the distinctive flavor of a Reuben sandwich.
Step 6: Prepare Rye Croutons (Optional)
Cube the Bread: Cut rye bread into small cubes.
Toast: Toss the cubes in olive oil or melted butter, season with a pinch of garlic powder, and bake at 375°F (190°C) for 10-12 minutes, or until golden and crispy.
Step 7: Serve and Garnish
Ladle the Soup: Pour the creamy Reuben-inspired soup into bowls.
Top It Off: Garnish with rye croutons, a sprinkle of Swiss cheese, chopped parsley, and a drizzle of Thousand Island or Russian dressing for extra authenticity.
Tips for Perfect Reuben Soup
Control the Salt: Corned beef and sauerkraut are naturally salty, so taste the soup before adding additional salt.
Cheese Melting: Use freshly shredded Swiss cheese for a smoother texture. Pre-shredded cheese often contains anti-caking agents that can result in a grainy soup.
Customize the Garnish: Add crispy bacon or even a fried egg for a decadent twist.
