Heat the oil in a medium-deep frypan over medium heat. Cook the leek, stirring regularly, for 3 mins, or until softened. Add the courgette, garlic, oregano, parsley and Dijon mustard and cook, stirring, for 1 min. Then add the stock, coconut cream and peas to the leek mixture, season with salt and pepper and bring to a boil. Cook, stirring regularly, for 3 mins or until the sauce is slightly reduced.