Stir constantly, making sure to scrape off the custard on the entire bottom and the corners of the pan, prevents scorching and ensures that the mixture heats evenly. Lift the spatula up occasionally to check if any large bubbles are bursting at the top of the mixture. Keep cooking and stirring until large bobbles appear. Then boil and stir for 1 minute. The custard should be shiny and drops intermittently when you lift up the silicone spatula. Add the butter to combine, if you are using it. Remove the saucepan from the heat.
Recipe by Namiko Chen of Just One Cookbook. All images and content on this site are copyright protected. Please do not use my images without my permission. If you’d like to share this recipe on your site, please re-write the recipe in your own words and link to this post as the original source. Thank you.