I am making flan for a dinner party this evening. The recipe indicates the flan should be baked for an hour before chilling. However, having never cooked flan before I am unsure what the flans consistency should be when it comes out of the oven. Is a little runny okay? Will the flan already be "firm," or does that happen during the chilling process?
It will firm up a little bit during chilling, but not much. It is certainly supposed to be firm enough to keep its shape on its own when taken out.
If you have baked creme caramel or cheesecake, then try to get it to a similar consistency as these. If you haven't, you may want to use a roast thermometer. The final temperature (assuming a traditional flan without starch or flour) should fall in the 85-90 Celsius range.
I find that the flan doesn’t set in the oven, even if baked for hour and fifteen minutes. However, it has always set when left in fridge overnight.