Original reddit post
Welcome to another technical challenge - the Pâte à Choux... Pronounced "Shoe Pastry" (confusing when you hear it for the first time on an English baking show), choux means "cabbage" in French. Which should give you a rough idea of what your bakes should look like, especially if you go for the small round kinds.
Like our other technical challenges, this is not a specific item but a baking technique. Choux pastry does not use a raising or leavening agent, instead it "employs its high moisture content to create steam, as the water in the dough evaporates when baked, puffing the pastry" (source : Wikipedia). Once you master the basic technique, you can use it to make various delicious recipes - sweet or savory, and maybe even come up with your own. For the basics, check out Sally's tutorial.
Popular recipes include Éclairs, Gougeres (which are savory, cheesy Profiteroles) or Paris Brest. For a non-French, unorthodox take on the challenge - try some delicious churros.