For the Strawberry Balsamic Preserves: In a small saucepan, add the strawberries, balsamic and sugar. Bring to a boil and then lower heat to medium and stire constantly, breaking up the strawberries with the back of a wooden spoon. Once the balsamic has reduced and a nice think jelly has formed remove from the heat and set aside. About 5-7 minutes
Add some butter to a frying pan and melt over medium heat. Add your bread and light toast one side of each slice. Then remove and on one piece of the toasted side layer cheese, strawberry, and spinach. On the other piece layer another slice of cheese.
Add a little more butter to the pan and add the pieces of bread. Cover the pan with a lid and ver medium low heat, start to toast and carefully watch the cheese. After a minute or two add the piece of bread with only the cheese on top of the other half and press down lightly with a spatula. After another minute or two flip the sandwich over and cook another minute until the bread is toasty and golden brown.