Preheat your oven to 180°C.
Peel and slice your potatoes, leek, garlic and courgette to around 0.5cm thick.
In a baking dish (roughly 20cm by 10cm), layer up your potatoes, leeks, garlic and courgettes, adding a little salt and pepper and chopped parsley between the layers. Pour over the hot vegetable stock and cover with tin foil. Put into the oven for around 30-40 minutes until the potatoes are tender.
Remove from the oven and top with the breadcrumbs, parmesan and olive oil. Return to the oven for a further 5-10 minutes or so until the top is golden brown.
Remove from the oven and top with a little more fresh parsley before serving.