One way to check if your custard is done is by using the wobble test. Yes, you read that right - the wobble test! It's like checking if a Jell-O dessert is set, but instead, you're gently shaking the custard to see if it's still jiggly in the middle. If it is, it's not quite ready, but if it's just slightly wobbly, you're good to go!
Another way to check is by using a knife or skewer to see if the custard is set. It's like checking if a cake is done, but instead of inserting a toothpick, you're inserting a thin knife or skewer into the center of the custard. If it comes out clean, your custard is ready, but if it's still goopy, you need to give it a bit more time.