Mix all of the marinade ingredients in a bowl, except the tempeh and olive oil.
Slice the tempeh in half lengthwise and then cut each half into 4, giving you 8 pieces altogether. If you’d prefer thinner pieces, slice each piece in half again.
Toss the tempeh slices through the marinade and allow it to marinate for at least 2 hours.
Meanwhile prepare the Russian dressing by mixing all dressing ingredients into a mixing bowl and whisk until smooth. Refrigerate until ready to serve.
When the tempeh has done marinating heat the olive oil in a pan over medium heat, cook the tempeh for 5 minutes or until brown on both side.
Pour the marinade over the tempeh and cook for another 4-5 minutes, turning occasionally, until the marinade has reduced completely and the tempeh is a lovely golden color. Remove and set aside.
Heat a pan over medium heat.
Spread a layer of vegan butter over 2 slices of bread.
Cook the bread, buttered side down, and spread a layer of dressing over one slice of bread.
Place vegan cheese on the other slice of bread, top with several slices of tempeh and a layer of sauerkraut.
Finally top the sandwich with the toasting bread, dressing side down.
Slice and serve immediately.