Start with the preparation of the shallot mix by placing a shallow pan onto medium heat and add the butter. Once melted add shallots, garlic, bay leaves, lemon thyme, seasoning and lemon zest. Cook until semi soft then add the cider and calvados; reduce the liquid until it has evaporated and leave to cool on a tray.
Separately, place the mussels into a hot pan; then add cider, bay leaves, lemon thyme, lemon zest and shallot mix. Cover with a lid to steam and cook the mussels for 2-3 minutes until they open.
Add butter, pepper, lemon juice and parsley, stir in and serve.