Heat grill to medium-low. Tear off two 12-inch squares of foil.
Layer marshmallows, chocolate chips, then strawberries in an even layer about 4 inches wide in center of one piece of foil. Place second sheet of foil on top and fold sides over 4 times to seal tightly.
Place covered pack on campfire grill or in skillet over fire, 4 minutes. Immediately cut open and serve with graham crackers for dipping.