Low and Slow
Don’t be tempted to hurry the process and steam your leche flan on full blast. The only way to get unbelievably smooth custard is by cooking it gently over a constant medium heat. High heat will inadvertently boil the custard and overcook it, resulting in scrambled eggs instead of luscious leche flan.
Watch Out For the Wobble
Test to see if the leche flan is done by giving it a little shake. The custard’s center should give a slight wobble to let you know it’s reached the sweet spot. If the whole custard jiggles vigorously, it’ll need a few more minutes in the steamer. If it doesn’t move at all, that means that the custard has over-set and is a little too stiff.
Keep it Cool
While it might be tempting to turn your leche flan out as soon as it comes out of the steamer, it’ll need to cool down completely before it’s completely set. Turning it out while it’s still warm will risk having the entire thing collapse because the cooked egg hasn’t had enough time to stabilize. It’ll be best to chill your leche flan in the fridge for a few hours in order to get the best possible set. Anyway, leche flan is best eaten with just the slightest chill from the fridge.