Welcome back to Aryeh Cooks. If you don't recall the first part of this post, well than go back and read it again.
Pastry cream is more of a custard than a cream (although it can have cream in it). And here comes a recipe:
1 1/2 cup dairy product (I made this twice, once with none fat milk and once with heavy cream)
Vanilla (the recipe uses a vanilla bean, I used vanilla sugar and you could probably use vanilla extract.
4 egg yolk (and this is where you could get your egg whites for your choux)
1/2 cup of sugar (I substituted some of this for vanilla sugar)
3 and 1/2 tablespoons of corn starch
1 tablespoon of butter (unsalted)
NOTE: this recipe will only yield enough for half of your eclairs so you should double it (I only made a half batch of the eclairs so this was fine for me).
There area number of different methods for separating egg whites from egg yolks, and you can learn about them from a Google search. I used the shell method. The only real advise I can give you on this is not to use eggs straight out of the fridge, warm them up first and they will be far easier to separate.
Add half of the sugar to the egg yolks and the other half into the dairy (you should add the vanilla flavor to the dairy). Put the dairy over the stove on low heat (the last thing you want to do it burn your dairy).
Cream the egg yolks and sugar together with the corn starch.
Now comes the bit that always scared me about custards. You need to bring the temperature of the eggs up slowly. If you do it to quickly you will have scrambled eggs in your custard. The way to do this is to slowly add the hot dairy into the egg yolks while mixing. Take your mixing implement with one hand and your dairy in the other. While mixing the eggs slowly pour a bit of the diary into the eggs and mix. When they are fully mixed add a bit more diary in. By the time you have mixed about half of the dairy in you should be OK to drastically speed up the combination. (Sorry I don't have pictures of this step, I was busy not messing it up)
Pour the custard base back into the pot and put back on low heat.
When your pastry cream has gotten cold and set put it into a pastry bag with a smallish star head on it.
Next take about a cup of chocolate chips and a teaspoon of vegetable oil and melt. Most cooks recommend melting chocolate over a double boiler or in a microwave, I have always done it on a stove at the lowest temperature setting.
Voilà you have made chocolate eclairs, congrats.
Earlier I mentioned that I made I made two batch of the pastry cream with two different dairy products. They resulted in two completely different textures with the heavy cream resulting in a stiff custard and the none fat milk resulting in a pudding like custard. For eclairs whole milk is probably your best bet. However, the heavy cream was for a chocolate eclair cake, which is a bonus on this episode of Aryeh Cooks.
I started with a regular chocolate cake (I use the recipe from the back of the Hersey's coco powder). Then I cut it into layers. Alton brown has a trick for this, he uses some wood and a saw blade. I have modified this for the soft chocolate cake and I use some wood and some fishing line (although very thin wire, like what is used to cut into large blocks of clay, would probably work better). I use some 1/2 inch square dowels I bought from home depot (I bought one length and cut it in half). You put the wood on both sides of the cake and using it as a guide you run the fishing wire through the cake. I find a sawing motion works best, but you will likely need to play around with this technique to find what works for you. Then spread the filling of your choice (I have used pudding, chocolate mousse and the pastry cream) onto a layer and place the next on on top.