Resident Chemist here, a useful dodge for improving even "shop-bought" mince pies. Get your hands on a 2 or 5 ml hypodermic syringe (don't ask me how, mug a drug addict, steal) and just before or after (It doesn't seem to mattter which) you warm the mince pies in the oven inject through the crust 2 mls of Rum or brandy or whiskey according to taste. It perks up even the most bland of shop bought