Make your garlic butter: Use a fork to mix the two ingredients together until well-combined.

Make your balsamic tomato jam: Melt 1/2 Tbsp of the garlic butter in a large skillet on medium heat. Then, add the remainder of the ingredients and stir. Allow the mixture to cook for about 5 minutes, stirring often. Then, use a potato masher or the back of a wooden spoon to mash the tomatoes together. Stir again and remove from heat.

Assemble your sandwich: Spread each piece of bread with a thin layer of garlic butter. Then, flip 'em and spread a thick layer of pesto on each piece. To half of the slices, add a generous amount of balsamic tomato jam and your mozzarella, and top that with the other piece of bread.

Cook 'em up: Melt a Tbsp of the garlic butter in a large skillet on medium-high heat. Turn the heat to medium and gently add each sandwich to the skillet, cover, and cook for about 3-5 minutes, or until the mozzarella is melted enough to hold the sandwich together. Gently flip each sandwich and cook for another 2-4 minutes, uncovered, until the bread is lightly browned and the mozzarella is melted.

Finally, plate 'em and eat 'em! They taste best eaten ASAP, so get to it! And as always, ENJOY. :)