Step 1: Prepare Your Station (Mise en Place)
Before you even think about turning on the heat, get all your components ready. This is the key to a smooth and successful sandwich-making process. Lay your four slices of rye bread on a clean cutting board. Squeeze your sauerkraut one last time to remove any excess liquid—you can press it between your palms or use a cheesecloth. Have your softened butter and a butter knife ready.

Step 2: Butter the Bread
Generously butter one side of each of the four slices of rye bread, spreading it evenly all the way to the edges. This is what will create that beautiful, golden-brown, crispy crust when you grill it. The buttered sides will be the outside of your sandwiches.

Step 3: Assemble the Sandwiches (The Art of Layering)
Flip the bread slices over so the buttered sides are down. Now, build your sandwiches on two of the slices. The layering order is crucial for both flavor and preventing sogginess:

1. Dressing: Spread 1 to 1.5 tablespoons of your Russian or Thousand Island dressing on the un-buttered side of each of the four bread slices.

2. First Cheese Layer: Place 2 slices of Swiss cheese on each of the bottom bread slices (the ones you will build upon). This cheese layer acts as a barrier, protecting the bread from the moisture of the fillings.

3. The Corned Beef: Gently pile ½ lb of the thinly sliced corned beef onto each sandwich. Don’t just slap it on; gently fold and layer the slices to create some height and air pockets. This makes the sandwich more tender.

4. The Sauerkraut: Place ½ cup of the well-drained sauerkraut on top of the corned beef on each sandwich.

5. Second Cheese Layer: Place the remaining 2 slices of Swiss cheese on top of the sauerkraut. This top cheese layer will melt down and hold the sauerkraut in place.

6. Top it Off: Place the remaining two slices of bread on top of each sandwich, dressing-side down, buttered-side up.

Step 4: The Low-and-Slow Grill
Heat a large skillet, cast-iron pan, or griddle over medium-low heat. The biggest mistake people make is using heat that is too high, which burns the bread before the cheese has a chance to melt.
Carefully place the assembled sandwiches in the hot skillet. You should hear a gentle sizzle, not a loud crackle.
Grill for 4-6 minutes per side. You can gently press down on the sandwiches with a spatula to help the components meld and ensure an even crust.

Step 5: The Flip and Finish
After 4-6 minutes, the first side should be a deep golden brown and the cheese should have started to melt. Using a wide spatula, carefully flip the sandwiches. Grill for another 4-5 minutes on the second side, until it’s equally golden and the cheese is completely melted and gooey.

Step 6: Rest and Slice
Remove the sandwiches from the skillet and place them on a cutting board. Let them rest for a minute or two. This allows the fillings to set slightly, making the sandwich easier to slice without everything spilling out. Using a sharp serrated knife, slice the sandwiches in half on a sharp diagonal for that classic deli presentation.