What to do when you have to lots of leftover pesto? Slather it all over sourdough bread and layer it up with tangy cheese and then toast the whole thing for a simply perfectly golden pesto grilled cheese sandwich. Cozy in some thick slices of summer tomatoes to make a sandwich ideal for the ladies lunch group or a light summer family meal.
Spread mayonnaise on outside of each slice of bread. Spread pesto on the inside of one slice of bread. To the other slice, add alternating slices of fresh mozzarella and cheddar.
Heat a skillet over medium high heat and when heated, add the sandwich. Lower the heat and cook until brown, checking periodically. Flip the sandwich, lower the heat some more and cover the skillet until the cheese is melted and the bread is golden brown.