Chive Pesto Grilled Cheese- two great tastes that taste great together

Mmmm, grilled cheese. Nothing says back to school like a grilled cheese sandwich.

Somehow, somewhere somebody taught me how to make a proper grilled cheese sandwich. For that I thank you. I know it seems simple enough but there are tricks.

• The bread should be well buttered on the outside and slathered with enough mustard (or, in this case, chive pesto) to add a tangy burst of flavor to the sandwich without overwhelming it. Aged cheddar and hearty rye can take more mustard than say mozzarella on ciabatta.
• Finding the ideal cheese-to-bread ratio is also important. I love cheese but I resist the urge to pile it on, too much and the cheese oozes out of the sandwich like Oobleck. No more than one layer of 1/4 inch thick slices of your cheese of choice are necessary.
• A cast iron griddle or skillet is best because a low even heat is key. Too hot and the bread is black but the cheese is still hard in the center, not hot enough and you lose precious cheese out the sides while the bread remains barely browned. Ideally the bread achieves a deep golden brown at precisely the same moment as the cheese has a total meltdown. (The sandwich pictured could have been a bit darker...oh well.) I have seen fights erupt over a grilled cheese cooked too quickly at too hot a heat. I set the burner on medium-low and adjust accordingly when I flip the sandwich over. Aiming for about 5-6 minutes a side, cheese soft but not yet oozing when I flip.