Dug out an onion & cheese tart out the freezer this morning, still needs a little defrosting (thank god for microwaves) and I think I'm going to serve it hot so the base isn't too soggy. So, how long would you recommend I bung it in the oven for? Normally I use the microwave for all reheating needs, but just want a crisp base this time and haven't a clue how much time is needed...