Created by gkwillow on December 19, 2011
Step 1: Whisk oil and vinegar in small bowl - add sliced tomato and turn to coat evenly with the marinade.
Step 2: Place 1 slice cheese on each slice of bread. Spread one with pesto and the other with mayo. Place 1 slice cheese on each slice of bread. Spread one with pesto and the other with mayo. Melt a tiny amount of butter in a skillet and place sandwich in the skillet. Cover the bread side facing up with a thin spread of mayo. Grill until golden, then flip to grill the other side.