Thejoshelkin

For the sauerkraut: Combine shredded cabbage with salt and water and weigh it down. Cover it and let it ferment in the fridge for 4-5 days. 

For the dressing: Combine all ingredients (mayonnaise, ketchup, sweet relish, finely minced onion, white vinegar, sugar, salt and pepper) in a bowl and set aside in the fridge.

Combine the mozzarella cheese and the swiss cheese. Slice the pastrami into smaller pieces so the loaf doesn't pull apart when eating. Heat the pastrami on a medium skillet. Add some water and cover to heat through and steam the meat. Cover the loaf in the dressing, then add a generous amount of the sauerkraut on top. Top with pastrami and the cheese. Bake in the oven at 400 degrees F for about 15 minutes until the cheese starts to brown and bubble.