Here's Nigella Lawson, making a quick chicken pot pie using puff pastry:
A few years ago -- Heavens, I need to do this again -- I made my own Chicago-style deep dish pizza. And yes, it's a pie, not a casserole.
Here's a wonderful video about Chicago-style pizza. Wait until you see the cooks at Gino's East putting the sausage into the pizza:
Thinking about pie always makes me hungry, but it can also take one's thoughts in a rather, shall we say, cosmic direction:
And then, of course, there's a whole other galaxy of uses for pie:
So whether you celebrate National Pie Day by baking a pie, eating a pie, or getting hit in the face with a pie, Happy National Pie Day!