Lightly butter each slice of bread. Place half of the slices, buttered side down in a skillet or griddle.
Divide cheese mixture evenly between the slices in the skillet.** Top with remaining slices of bread, making sure to leave the buttered side up.
Cook over medium heat until bread is lightly browned. Flip, and cook remaining side until lightly brown and cheese is melted.
Notes
¼ tsp. granulated garlic can be substituted for the clove of minced garlic
For a fuller flavor, mix up the sandwich filling several hours ahead of time, and refrigerate until ready to make sandwiches.
You want the cheese mixture to nicely cover the surface of the bread, but don't pile it too high, because you'll end up having a hard time keeping the sandwiches together once the cheese melts.
Leftovers taste best if you reheat them in a lightly buttered skillet, over low heat. Flip the sandwiches halfway through reheating so both sides get a bit crispy again.