Note: This pâte à choux recipe is enough to make about 64 cream puffs. We did about 4 batches to make about 250 in total for an 18" high croquembouche. We made them in batches so as to not overwhelm our mixer. You will need to make multiple batches depending on what size croquembouche you’re making, the size of your cream puffs, and how much filling you use. Add your milk, water, salt, sugar, and butter to a medium saucepan and bring it to a boil. The butter should be melted at the same time the milk starts to boil, so remove the pot from the heat to let the butter melt if needed.
Once your milk mixture is boiling and the butter has completely melted, take your pot off the heat, add in your sifted flour, and mix together until it looks like mashed potatoes. It is best to use a wooden spoon, but a spatula is fine too.
Turn the heat back on to medium-high and continue to stir and keep it moving to dry out the dough.
Once you see a browning layer on the bottom of the pan the dough is dry enough. This is important, as it will help your cream puffs “puff” and ensure that they have a hollow center for the cream filling.
Put the dough into the bowl of a stand mixer with the paddle attachment and begin to mix on medium speed to cool it down, this should take about 30 seconds to 1 minute. When you can place your hand on the side of the bowl without it feeling too hot, it’s done.
Slowly add in your eggs one at a time while mixing on low. Mix until the dough slowly falls in a v-shape off of your paddle.
Prepare a pastry bag with a small metal round piping tip. Fill the piping bag with the pate a choux batter.
Prepare a baking sheet pan with parchment paper. Chef Christophe is using a “silpain” baking mat on a cookie sheet for maximum airflow and evenly-baked cream puffs. Pipe the pâte à choux rounds slightly smaller than your desired final size (about 1-inch), as they will “puff” and expand in the oven.
Gently smooth the pointy top of the cream puff with a damp fingertip.
Bake the cream puffs at 350°F for 25-30 minutes until golden brown. Do not open the oven door or your cream puffs could collapse.
Cool the cream puffs completely to room temperature on a wire rack, for about 30 minutes.