Place a pan on the stovetop to warm over medium-low heat while you prepare the sandwiches.
Using a butter knife or sandwich spreader, spread the butter across one side of each slide of whole wheat bread.
Turn the slices of bread over and spread the mayonnaise evenly across the non-butter side of the bread. Add the pesto evenly over the mayonnaise, if desired.
Place two slices of provolone on one of the slices, overlapping the slices in the center, as needed.
Place the two slices of turkey over the provolone, similarly overlapping the slices.
Place the slices of bread together (butter-side out) to form a sandwich and place on the warmed pan. Without raising the heat (you don't want to rush this process), cook until the bottom slice of bread is golden brown and the cheese starts to melt off the sides, about 4 to 5 minutes. Flip carefully with a spatula and repeat.
Wrap the sandwich snugly in a sandwich bag or aluminum foil, label carefully with your name and date, and place in your bag for your commute to work.
At lunchtime, place the sandwich on a plate and warm in the microwave for 1 minute for maximum cheese melt.
Eat with a knife and fork—under the glow of your laptop.