Slice off one side of the zucchini skin, then use a melon baller or small spoon to remove the insides, creating a courgette boat (zucchini boat). Chop the flesh of the zucchini into small pieces, then sauté them with lardons and chopped onion for 7 - 8 minutes until they are tender.
Stuff the courgettes with this mixture (leaving a little room on top), then bake in a moderate oven (Mk 4 - 350°F - 180°C) for 15 minutes. Break 3 eggs into to each courgette and sprinkle mozzarella on top. Bake for a further 3 minutes. Remove from the oven, sprinkle with chopped parsley, and enjoy.