as a child, and one of five kids, money was tight,
my mam would make 'poor' pie
it was full of potato, onions and carrots and any other veg she had in the house and a oxo cube or two mixed it, she made her own pastry too.
corned beef hash....mashed potato..onion and corned beef all mashed up..or make it like a stew, diced up root veggies and lots of potato, add the corned beef at the end to warm through.
I make curry cheaply on those 'skint' days, I use as little chicken as possible, and add lots of onions and chickpeas, 2 chicken breasts can go a heck of a long way
also if we have had a roast chicken, I will use the left over chicken for another meal, then boil down the chicken to make a stock for a soup...I can get 3/4 meals for my family with a chicken.