Heat the oven broiler on high. Put the marshmallows on a foil-lined baking sheet and broil for 1-2 minutes or until they're good and brown on top. Keep your eye on the 'mallows because they can burn quick. Alternately, you can roast the marshmallows in an outdoor fire.
Add one piece of chocolate to a graham cracker square. Top with the marshmallow, 2 strawberry slices and a few chopped mint leaves. Cover with the other graham cracker square and press down lightly. Repeat with the remaining ingredients.
The heat from the marshmallow should melt the chocolate. If it doesn't, 20 seconds in the microwave should do the trick.