In a large cast iron skillet blacken the fish, When it is done set aside.
Mix the thousand island dressing and the sauerkraut together.
For this step I use a electric skillet, then I can make all four at one time. Butter one side of the bread. Then place the buttered side down in the skillet. Then place one slice of Swiss cheese on each slice of bread. Then place one peace of fish on each and then the sauerkraut. Then one slice of Swiss cheese and the other slice of bread butter side up.
Cook on both sides until hot all the way throw.