In a medium saucepan, combine the milk and butter, and bring to a boil over medium heat. Add the salt, sugar and flour, and stir vigorously with a heatproof spatula. Cook, stirring constantly, until a dense dough forms that pulls away from the side of the pan, about 3 minutes.
Add the dough to a stand mixer fitted with the paddle attachment. On low speed, beat in the eggs one at a time, scraping down the sides of the bowl between additions to make sure everything is evenly mixed.
Line a cookie sheet with parchment paper. Using a 1-ounce scoop, drop the dough, 1 inch apart, onto the prepared cookie sheet. Bake until puffed and golden, 35 to 40 minutes. (The puffs should feel light when you pick them up.) Make sure to keep the oven shut until at least the halfway point -- if you open the oven before 20 minutes have elapsed, the puffs will deflate and you won't be able to get the texture back. Remove the puffs from the oven and prick each one on the side to allow the steam to escape. Let cool completely.
To dip in chocolate: If desired, dip the tops of the puffs in Warm Chocolate Ganache, shaking off the excess. Place on a platter and sprinkle with sliced almonds. Let stand for about 30 minutes, to set the glaze, before eating.
Warm Chocolate Ganache:
Heat 1 inch or so of water in a medium saucepan over low heat. Put the chocolate chips and cream in a heatproof bowl that fits snugly into the saucepan without touching the water. Heat, stirring, until the chocolate melts and the mixture is smooth, about 5 minutes.