Preheat your conventional oven to 180˚C (356˚F). Add the feta, oil, oregano, garlic and preserved lemon to a small roasting tin and cover with foil. Bake for 10-20 minutes until the cheese is soft. Crush the softened feta down with the garlic and lemon, removing the skins and rind. If you find the sauce is too thick, loosen with a little water or lemon juice. Season to taste and let cool.