I am making a chicken pie. I've made it before with just a pastry shell on top but I'd like to line the dish with pastry this time. Will I need to blind bake the base of my pastry first? Is it then also necessary to seal the pastry with egg?
A Google search led to Pepperidge Farm's recipe for Chicken Pot Pie. Since they are the big name in the US for puff pastry, I tend to trust them.
They recommend lining the pan with a defrosted, lightly rolled sheet of puff pastry and pricking it with a fork before blind baking covered with aluminum foil for 25 minutes at 400F (~200C). Don't use pie weights, that will interfere with the 'puff'. They don't call for any egg wash or seal, and I can say from experience with the stuff that it isn't necessary.
They fill the baked bottom layer with the chicken filling, add a lattice top of puff pastry, then bake the whole thing (on a sheet pan or cookie sheet) for 45 minutes (or until the filling is bubbly and the lattice top is brown and puffy).
Be ready to put aluminum foil along the edge if it seems to be getting too brown.
I make individual chicken pot pies using fresh puff pastry I made myself. Although it's not absolutely required, I always blind bake the crust bottoms. It makes for a more consistently crispy and flake crust too and bottom, and since I make individual pot pies, the bottom is what people see on their plate when serving.
Additionally, the blind baking assures the bottom crust will be stiff enough for the pie to pop out onto the plate, whereas not blind baking may cause the crust to stick to the pie plate a little bit making a sloppy serving of pot pie.
I blind bake the bottom. In my experience, it's the only way to get that dough to cook-- I suppose because liquid filling right next to raw dough keeps it, the dough, from reaching cooking temperature.
I have a neat trick for the pie weight-- pennies! They're made of copper so the conduct heat well, and help the blind crust cook from the top down as well. I put them in parchment paper I've prepared using Heston Blumenthal's tip: cut a large enough square, ball it up, un-ball it up, and then do this another 4 times. A the little crinkles allow the parchment to take the exact shape of the blind crust.
I usually take the weight off of my crust at the end and give it 5 minutes more minutes. Recently I have taken to applying an egg wash at this point. It makes a good seal.
I don't believe in docking or pricking. This is just my opinion, and I've never conducted a side-by-side test, but I believe it prevents the pastry from puffing during the blind bake because it lets the steam out, and it causes sogginess during the second bake because it lets the liquid in.
I don't use puff pastry though, so maybe that's the difference. I use regular "3-2-1" pie dough, 3 parts flour, 2 parts fat, 1 part liquid. Plus salt.
I just did a pie with no blind bake and it was fine. Cooked it a little longer, so maybe 30-40 mins in the oven. No pricking, no nothing, just put the packeted puff pastry in the base with some butter to help it not stick. It wasn't soggy or undercooked. Judging by the responses above it sounds like a blind bake is preferable, but I would say far from essential.