To Make the Thousand Island Dressing:

1. Combine all ingredients in a bowl, stirring well. Store in the refrigerator.

To Make the Sandwich:

1. Start by steaming your tempeh. This is optional, but will make it easier for the marinade to absorb and reduces the slightly bitter flavor of tempeh. Cut the tempeh in half, lengthwise, use a steam basket over a pot of water and heat over medium, covering the pot. Steam for about 20 minutes. Allow to cool slightly and carefully divide the tempeh into thin slices. Lay the slices in a shallow container, and pour the marinade over the tempeh. Allow to marinate for about 30 minutes (or overnight).
2. You can either bake or pan fry your tempeh. To bake it, preheat oven to 400°F. Place tempeh slices on a baking sheet lined with parchment paper and bake for about 15-20 minutes, flipping and brushing with marinade halfway through.
3. To fry it,  lightly coat a skillet with avocado oil and heat over medium. Place the strips in the pan in an even layer and sear each side for about 2-3 minutes, pouring the marinade over them before flipping.

To Assemble:

1. You can toast or grill the sandwich
2. To make the toasted bread version, toast your bread and then spread dressing on each slice. Layer each sandwich with tempeh and sauerkraut.
3. For the grilled version, lightly coat a frying pan with avocado oil, and preheat over medium. Assemble the sandwich by spreading dressing over each slice of bread and adding a layer of sauerkraut and tempeh. Carefully place the entire sandwich on the hot pan and grill each side for a minute or two or until lightly browned.