Butter Bean and Leek Pie

Yield: 1 Servings
2ozButter beans; (or one medium can) (up to 3)
2lgLeeks; chopped
1tbVirgin olive oil
1Crushed clove of garlic
4ozChestnut mushrooms; chopped
1Courgette; chopped
1tsYeast extract
1/2ptSoya milk
1Veggie stock cube
1lgPinch mace
1tbCornflour; (up to 2)
Salt and pepper
6ozPuff pastry; (I buy it ready made) (up to 8)