In a small saucepan, combine fresh blueberries, sugar or honey, and lemon juice. Cook over medium heat until the mixture thickens and becomes jam-like, about 5-7 minutes. Stir occasionally.

Spread a thin layer of softened butter on one side of each slice of bread.

On the unbuttered side of two slices, add a slice of melting cheese, followed by a layer of blueberry filling, then top with another slice of cheese. Place the second slice of bread on top, buttered side out.

Heat a skillet over medium-low heat. Place your sandwich in the skillet and cook for 4-5 minutes until golden brown and the cheese starts to melt.

Gently flip the sandwich with a spatula to cook the other side for another 3-4 minutes until crispy and the cheese is melted.

Remove from skillet and let it rest for a minute before slicing. Serve warm and enjoy!