A repost from the Witch’s Kitchen blog, which will soon go away.
Choose a bread you like; a nice, white Italian bread works best. Spread each slice of bread with pesto. Layer 1 slice of bread thinly sliced turkey, tomato slices, and sliced mozzarella. Put under the broiler for a few minutes, until the cheese is melty and slightly bubbly. Top with the other slice of bread.