Lay all bread slices on work surface. Place a slice of cheese on each piece of bread. Place 2 slices of Canadian bacon on each piece of bread. Place a slice of tomato on half the slices. Assemble the sandwiches.
Spread butter on each side of sandwich. Heat a large nonstick pan and melt remaining butter in it. Pan fry the sandwiches until golden brown. Slice sandwiches on diagonal and serve with cream of tomato soup. Great on a cold day.