Mix together the parsley, garlic, breadcrumbs, cheese, grated rind of one lime and juice of half the lime. Season and mix with the olive oil. Blend thoroughly.
Spilt the mussels in half and discard the empty shells leaving the mussel meat in the half shell. Top each mussel with the breadcrumb mixture and arrange in a shallow ovenproof dish.
Bake for approximately 10-15 minutes until golden brown.