-
1
Preheat oven to 400F.
-
2
and lightly grease 2 large baking sheets.
-
3
In a heavy saucepan bring water, butter, and salt to a boil over high heat and reduce heat to moderate.
-
4
Add flour all at once and beat with a wooden spoon until mixture pulls away from side of pan.
-
5
Remove pan from heat and add eggs, 1 at a time, beating well after each addition.
-
6
Continue beating until batter is very smooth and falls softly from spoon.
-
7
Drop pate a chou by rounded teaspoons 1 1/2 inches apart onto baking sheets and bake in upper and lower thirds of oven, switching position of sheets halfway through baking, 25 minutes, or until puffed, golden, and crisp.
-
8
Transfer puffs to rack and cool.
-
9
In a small heavy saucepan cook onion slice in butter over moderately low heat,stirring, 3 minutes and discard onion.
-
10
Stir in flour and cook roux, stirring, 3 minutes.
-
11
Add milk in a steam, stirring until smooth, and simmer, stirring, until very thick, about 2 minutes.
-
12
Add Gruyere, stirring until melted.
-
13
Stir in salt and pepper to taste and cool filling.
-
14
With a small sharp knife poke a hole in top of each puff and gently pull apart just enough to fill with a rounded 1/2 teaspoon of filling, reclosing puff.
-
15
Arrange filled puffs on baking sheets.
-
16
Chill puffs at least 1 hour and up to 4.
-
17
Preheat oven to 350F.
-
18
Bake chilled puffs in middle of oven 10 minutes (do not bake longer because filling may seep out of puffs) and serve immediately.
