This has always been a challenge for me with a baked egg dish. How to tell when it's done cooking inside. Generally if the top is golden brown, it's done, but it's also very easy to over-cook these. The best way to tell if it is done is to use a knife and cut a small slit in the center and just press slightly against the quiche. If there is still liquid egg, you need to cook it more. If no liquid pools when you press sideways, then it's done.