1. Pâte à Choux (paht ah shoo)

2. Thick paste made on the stovetop from a roux with the addition of eggs.
Choux pastry paste is versatile and used to make many items such as cream puffs, éclairs, profiteroles, and croquembouche.
Uses fat to puff up in volume
Pâté à choux relies upon the high water content in eggs as leavening (steam) which will cause the pastry to puff up when baked
Choux Pastry

3. Mixing Method & Baking Reduce temp. so overbrowning doesn’t occur
Boil fat & water so the fat is dispersed throughout the liquid.
Add flour & stir vigorously over low heat until ball forms
Remove from heat. Stir in eggs until smooth, forming a puff paste.
Important that each egg is incorporated before adding the next.
After all the eggs are incorporated, the dough should be stiff enough to hold a peak when a spoon is lifted out of.
Drop or pipe onto baking sheet
Bake in hot oven so steam causes puff to rise
During baking, the crust traps steam inside, generated from the moisture in its ingredients and hot air from the oven, plus leavening from the beaten eggs.
It is this principle, which causes them to become inflated, hollow and stay puffy.
Reduce temp. so overbrowning doesn’t occur
If they are removed from the oven too soon, the structure of the shell has not solidified, it will collapse.

4. Cream Puffs The goal in making the perfect cream puff is:
Crispy crust
Light hollow interior
Golden brown
Its round, somewhat hollow center can be cleaned out and filled with whipped or pastry cream, and sometimes topped with powdered sugar or a chocolate glaze.

5. Eclairs
An éclair is a delicate, individual pastry made with choux paste
The dough is piped from a pastry bag in an oblong or log shape on baking pans, and baked until it is crisp and hollow inside. 
It is either filled from a hole made in one end, or split lengthwise and filled.  The filling is traditionally a vanilla pastry cream or whipped cream and usually topped with a chocolate fondant or confectioners’ glaze
Other fillings include coffee and rum flavored custard, fruit flavored fillings or chestnut purée, and the topping is usually flavored the same as the filling.

6. Characteristics of Choux Pastries
A properly baked choux
Retains its puffy shape
Outside that is crisp and fairly dry
An all over golden color
Inside should be somewhat hollow with a slightly moist crumb on the inside