So I'm thinking about how I would approach this if I were in your shoes.
This will be a fun mental exercise for me and hopefully helpful to you.
First, what are my short term and long term goals.
Short term -supply pies for immediate needs for unknown amount of time and unknown number of pies. Establish whether or not this is worth pursuing in the long term.
Long term-how many pies can I make per day/week once I get a system going and could I sell my pies to other restaurants in the area?
How long do I anticipate making pies and how many for just this restaurant? A typical restaurant of good size would have a choice of desserts but I think they would still need more than one pie per day so let's say two per day and open six days a week. So twelve pies per week. At 14 oz of dough for a two crust pie that's about ten and a half pounds of dough per week. Can I make that all ahead of time?
How much time do I have per day to make the pies? How much do I charge per pie to cover the materials, time and effort to make two pies per day? What if they call and need fewer pies? What if they need more pies? Are they guaranteeing they will buy a certain amount of pies every week? How much notice am I getting? How quickly do they need the pies once they call with an order? Will that give me enough time to make the pies they need? How much notice/time do I need to make pies?
Setting aside the filling needs for a moment, I need crust for twelve pies per week. One amount for bottom crust only, twice as much for covered pies, something in between for lattice crusts.
Twelve per week is 48 pies per month and 576 pies per year.
What equipment do I need to make pie dough for twelve pies per week? Do I have that equipment?
Do I have a Health Dept. approved place to make the pies?
If demand for the pies increases and I can sell them to other places, when is it worth it to invest in some equipment like a commercial mixer, pie press machine, pie pans, etc?
Can I or should I make gluten free pies? Other allergy concerns?
This has all been pretty much stream of consciousness writing so perhaps a bit jumbled but I think you can see what I mean. Anyway, this all reminds me of the movie "Waitress" a small indie movie about a waitress who makes pies at a pie shop owned by Andy Griffith. If you're making pies, you should see this just for the visual effects about pies. And it's a really good movie too.