Baked mussels

I found two boxes of New Zealand mussels in our freezer- which reminded me that I planned to bake them like two weeks ago. It is very easy to prepare but has to be eaten right away. I don't really like reheating them so it's best to make a fresh batch for serving since it takes only fifteen minutes to bake. Thirty minutes at the most if you are to include the the preparation of garlic butter and grating fresh parmesan cheese and bread crumbs. It is a delicious appetizer and served with lemon slices.