Mix together the pesto sauce and Parmesan cheese and then spread on one slice of bread. Layer the muenster cheese on top followed by tomato slices, cheddar cheese, and top with the other slice of bread. Butter the outside slices of bread and then cook in a skillet over medium heat until golden (cook it slow so the cheese has to melt before the bread cooks too much). Flip and cook the other side until golden. Cut in half and serve warm.