Scummy, I have a total STACK of recipes which fit the bill!
My basic low fat tasty "pie" is not so much a recipe but a bung it all in as follows....
This is for two greedy people.
You basically need plenty of veg.... 3 big portions of low carb veg such as mushrooms, leeks, (sliced thinly), carrots,(diced finely) onions, broccoli,green beans, cauliflower, turnip....
cook the veg in about a half cup of stock ( I use Marigold vegetable bullion as it is very tasty, if a little salty) for about 5 minutes.
Put the veg in an ovenproof dish ; "fry" in a little more stock a smallish portion of either chicken, fish,Turkey or bacon. ( I use only one chicken breast between two as the veg pads it out so much. ) Even cheap wafer thin ham works quite well .
Add this to the veg in the dish , then make the sauce in the same pan using the sticky veg/ chicken/fish juices as follows.
Add half a pint of milk to the pan but reserve a small dribble into which you mix a rounded desertspoon of cornflour. Add the cornflour/ milk to the milk in the pan and bring to the boil to make what is basically a fat free white sauce. Cook for a few minutes. I often add a tablespoon of dried parsley/ mixed herbs at this stage.
Pour the sauce over the other stuff in the dish.
For the topping , take one large( or two small) potato and chop into short "matchsticks." ( first slice in half lengthwise; the rest is easy) then sprinkle over the dish.
Cook in a hot oven for about 45 - 60 minutes till the tatties are brown and bubbling.
It is best left to stand for 15 mins before eating.
You can make lots of permutations of the above using different veg/ meat. It is deliciously filling, and makes a huge quantity.
There is plenty in this amount to feed one small ( not too fussy !) child.