Preheat oven to 425˚F. Line a rimmed baking sheet with Silpat or parchment paper.
In a medium saucepan, combine water, milk, butter, sugar, and salt. Bring just to a boil over medium heat then remove from heat and stir in flour all at once with a wooden spoon.
Once the flour is incorporated, place back over medium heat stirring constantly for 1 1/2 to 2 minutes to release extra moisture and partially cook flour. A thin film will form on the bottom of the pan and dough will come together into a smooth ball.
Transfer dough to a large mixing bowl and beat using an electric mixer on medium speed for 1 minute to cool mixture slightly. Add eggs 1 at a time, allowing to fully incorporate between additions. Beat another minute until dough is smooth and forms a thick ribbon when pulled up.
Transfer the dough to a piping bag with a 1/2 inch tip, or a ziplock bag, and cut a 1/2 inch corner off. Pipe 12-14 puffs, each 1 1/2” diameter and 1/2” tall rounds. Keep them 1" apart. If you get peaks, wet a fingertip lightly with water and smooth them out.
Bake at 425˚F for 10 minutes in the center of the oven. Without opening oven, reduce temp to 325˚F and, bake 20-22 min longer or until golden brown on top. Transfer to wire rack to cool completely.