Freezer storage: If you are going to freeze these, let them cool completely but don’t add the spinach.Wrap each sandwich in a piece of aluminum foil or parchment paper and place them all in a large Ziploc bag or an airtight container.Freeze for up to 3 weeks.Let them defrost in the fridge for 6 hours before unwrapping them then wrapping them in a damp paper towel and microwaving for 1-2 minutes or until heated to your liking. Add a handful of spinach and serve.