I’ve had Marie Calendar’s pot pies and the filling to me, as I remember it, was just a regular ol’ gravy. Looking at their ingredient list online, it doesn’t seem to be thickened with anything but flour and corn starch.
Personally, I like to thicken with flour most of the time, as corn starch makes food a bit glossy and gelatinous. So I’d start with using flour, and being careful with how much roux or slurry (a mix of flour and cold water) I mix into the liquid being thickened.
If you want to use root vegetables, you need an immersion blender. For Thanksgiving, I just blended the turkey juices with the veggies the bird was resting on as it cooked. The result was a nice, thick, smooth gravy.
At Christmas, I whisked blond roux, port, and and a knob of sweet butter into my goose juices after ladling off as much of the fat as I could. This produced a delicious gravy.
In both cases, you need to add salt and pepper to taste. If you want herbs as well, stick them in the roasting pan with the bird and remove them before you blend the juices.
Marie Callendar’s pot pies are delicious.
64 grams of fat (24 saturated) per serving delicious.
Whoa. My cardiologist will be soooo mad that you informed me of this!