Mille Feuille can be translated as "a thousand leaves" and rightfully so, as you can really feel your teeth sinking into layers and layers of puff pastry in just one bite. Each layer sandwiches a vanilla pastry cream which provides a nice subtle sweetness with a smooth texture to balance out the flaky pastry.
I found this recipe when I was searching the internet for problem-solving tips for my pastry cream. Just a little tangent here: I had 4 failed attempts before finally getting it right. My first attempt of making pastry cream yielded vanilla-flavored scramble eggs, my second was too runny, I made a huge mistake in the third batch by forgetting to add sugar, and the fourth was firmer than the second attempt, but it wouldn't hold its shape. In my search, I found multiple uses for pastry cream with one of them being to make Mille Feuille.
I found a lot of different recipes for Mille Feuille online, some that looked fancy with fruit and/or chocolate, and some that were plain. I consulted with a friend who's knowledgeable in French pastries, and he advised me to make mine more traditionally - no chocolate and no fruits.
It all comes down to preparing 2 parts: puff pastry and pastry cream.