Preheat oven to 180°C.
Cut the courgette in half lengthwise. Scoop out their flesh; chop and set aside.
Place the courgette shells in a roasting tin, hollowed side up.
Finely chop the leek, garlic and mushrooms.
Add these to a frying pan, spray over them the oil, then gently sauté them for 10 minutes under cover. Stir in the spices and chickpeas, lemon juice, salt and pepper. Add the freshly chopped coriander.
Spoon the mixture into courgette shells.
Bake for 30 minutes or so, until the courgette is tender.