Mix coconut and a few drops of green food coloring and water, if needed. This will be the "lettuce." Preheat oven to 350 degrees.
Place desired amount of vanilla wafers round side down on cookie sheet. Place a mint patty on top of each. Place in hot oven just until patty is softened. Remove from oven, sprinkle the colored coconut on top and place another wafer (round side up) over and press down slightly. Brush the "hamburgers" with water and sprinkle on sesame seeds.