1.Combine lemon juice, oil, parsley, garlic, salt and pepper in medium jug.
2.Drop calamari into a medium saucepan of boiling water, reduce heat. Simmer for 10 minutes or until calamari is tender; drain. Combine calamari and half the olive oil mixture in a non-metallic bowl. Cover, refrigerate for 4 hours or overnight.
3.Combine mushrooms and remaining olive oil mixture in a non-metallic bowl. Cover, refrigerate for 4 hours or overnight.
4.Wrap asparagus spears with prosciutto Cook on a preheated oiled grill pan or barbecue until browned lightly and tender.