23 The reason why this is important is because, in order to get pastry cream that sticks enough to slice through, which is important if you’re gonna be using that pastry cream in the tart. You do need to really get the maximum thickness power of the egg, which means you wanna boil the egg. But if you boil the egg, and you don’t add some sort of protection, you get really thick scramble egg basically and this, of course, the starch will prevent that from occurring.