Frugal Pie - PUBLISHED

Rain, Hail, and Baked Beans pg 28

https://www.thespruce.com/pork-pot-pie-romancing-the-leftovers-913124

1 - I have a bad cold so I can't taste properly, but my Ben liked this just the way it is. I will therefore graduate this recipe to the next level; hence the wisdom of having a tiered testing system.
2 - I tried the Frugal Pie using leftover chicken and the result was fine but not stellar. The chicken and potato where too similar in intensity of flavour. I wonder, if I added a sharp cheese or a grainy mustard to one or the other?
3 - Made with pork again, and again, excellent.
4 - Tried a couple of things: (a) in ramekins to try and keep things neat: physics got in the way - when pushing down on the potato topping to cut through with eating implement, the filling gets pushed out of the way - difficult to get satisfying ratio of potato-to-filling. Conclusion: better to have it in a pie plate; some foods are better even if they look messy on the plate (like sloppie joes); (b) had lots of the meat so I doubled the recipe, which made me wonder about establishing a #of cups or oz of filling x pie dish, which would allow for the amount of meat to use up, increasing the usefulness in a frugal/sustainable kitchen; I'm guessing measuring by volume (cups) would be better since the mass of a piece of celery is likely less than a piece of meat. More veg if less meat, less veg if more meat - the herbed goo should balance the flavour and a standard quantity of potato topping should keep the experience pleasant.
5 - Making it brothier is good. Too much broth isn't because it'll just soak into the potato. Just enough to activate the flour to thicken and coat the meat and veg. I'll keep it at Test 2 until I make it again - the quantity of liquid, which was originally 1/4 cup, was increased, but it may take more than 1/2 cup. The Chicken Pot Pie takes 1 1/2 cup of liquid, but I think that would be too creamy... or would it? My fear is that too much would ruin the potato topping. Wait a minute, people love gravy on their potatoes! Screw it, I'm increasing the goo factor to 1 cup!

2 Tbsps butter or bacon fat
1 onion, diced (TO DO: Measure the total quantity of veg and meat)

2 stalks celery, diced

2 carrots, diced
Optional 4oz mushroom, diced
1 Tbsp flour
1/4 1 cup broth (can be liquor from the roast)
1/4 cup Tbsp milk

1 sprig thyme, rosemary or sage
1/2 tsp salt
1/4 tsp pepper

8 oz cold cooked red meat (or with chicken, see comments 2, above)

1 lb potatoes (cold or already mashed)

1. Sauté onion, celery, carrots and potatoes in butter until cooked through and starting to brown, about 10 minutes.
2. Meanwhile, mince the meat by hand for small but recognizable chunks.
3. Preheat the oven to 400F.
4. Add flour to the sautée mixture, stirring well. Cook one minute, at least, or until well browned. This is important - cooking the flour in the buttered vegetables means the flour is absorbing all the liquids and fats in the pan, then cooking so that when you make the sauce, it will have carried all the lovely browning flavour with it, and it won't taste floury. 
5. Dump the broth and then the milk into the vegetable mixture and stir thoroughly. Add the thyme, salt and pepper. Cook over medium heat stirring constantly until the broth thickens and gets bubbly. 
6. Mix in the meat and put in a pie plate or casserole dish.
7. If they're not already mashed, prepare the potatoes with 3 Tbsps of milk or cream, and butter, to taste, along with a pinch of salt.
8. Layer the mashed potatoes on top of the meat mixture and put in the hot oven for 35 minutes or until the top browns.