Preparing the chicken:
Start by removing and shredding or chopping the meat from a rotisserie-style store-bought chicken ... or you can use any leftover chicken you may have. You'll need a good 2 -3 cups.
There really are no exact measurements to this, use the amount of chicken or veggies you prefer.
In a large pan set to medium on stove top.
Add the following:
A few pats of butter
1/2 onion, finely diced
1 celery stalk, finely chopped
Sprinkling of salt and pepper
Saute just a few minutes, then sprinkle in a couple of tablespoons of flour. Stir to coat veggies in flour and cook for another few minutes to cook out raw taste of flour.
Next, add in a couple of cups of chicken stock. Whisk, then add a few splashes of heavy cream or half-and-half.
Allow to come to a simmer and add the following:
1/2 bag of frozen mixed vegetables (or any combination of fresh or frozen carrots, green beans, peas and/or corn equivalent to a couple of cups.)
2 - 3 peeled potatoes, chopped in small pieces
Then, add in any dried herbs you prefer. I use herbs de Provence, but whatever you like is fine, too.
Once mixture starts to come to a slight boil, reduce to low and simmer until thickened. Taste and adjust seasoning. Then, I find that putting the mixture into the fridge for about 30 minutes really helps get it to the consistency you need.
Then, pour mixture into a large, greased pie dish or round casserole dish.
Your choice of a (thawed) frozen pie crust, a refrigerated pie crust or (thawed) frozen puff pastry can be used on top. Or, if you're the baker-type, whip up a homemade pie crust. (I'm just not the baker type). I prefer puff pastry (as shown below).
For a pie crust-style top, be sure to cut a few slits in the crust after placing it on the "pie." Seal edges. Brush pie crust with an "egg wash," a mixture of 1 egg and a few splashes of water whisked together. Sprinkle pie with a small amount of kosher salt.
For a puff pastry-style crust, roll pastry on a lightly floured surface to thin it out a bit, then I do a lattice pattern. Start by cutting the puff pastry into 10 - 12 strips.
Then, weave the strips onto the filling.
Bake at 325º on middle oven rack for 45 - 50 minutes. You'll want to bake the pie on a large baking sheet to catch spillovers. You'll know it's done when filling is bubbly and crust is flakey and beginning to brown.
Allow to "rest" after baking for 15 minutes to allow pie to, and enjoy !