Prepare the sauerkraut: If your sauerkraut is very wet, squeeze it gently in a clean kitchen towel or paper towels to remove excess moisture. This prevents the sandwich from becoming soggy.

Assemble the sandwiches: Lay out the four slices of rye bread on a clean surface. Spread 1 tablespoon of Russian dressing evenly on one side of each of two bread slices (these will be the bottom pieces). Spread the remaining 1 tablespoon of Russian dressing on one side of the other two bread slices (these will be the top pieces).

Layer the ingredients: On the two bottom bread slices (dressing-side up), place two slices of Swiss cheese. Divide the pastrami evenly and pile it high on top of the cheese. Top the pastrami with half of the drained sauerkraut on each sandwich.

Close the sandwiches: Place the remaining two bread slices (dressing-side down) on top of the sauerkraut, completing your two sandwiches.

Butter the bread: Generously spread 1 tablespoon of softened butter on the outside of each sandwich (the non-dressing side of the top and bottom slices). Ensure full coverage for even grilling.

Grill the sandwiches: Heat a large skillet or griddle over medium heat. Once hot, place the buttered sandwiches onto the skillet. Cook for 4-5 minutes per side, or until the bread is golden brown and crispy, and the Swiss cheese is fully melted and gooey. You may need to press down gently with a spatula to ensure even contact and melt the cheese thoroughly.

Serve: Remove the sandwiches from the skillet. Let them rest for a minute, then slice each sandwich in half diagonally using a sharp knife. Serve immediately with extra Russian dressing or a pickle spear, if desired.