Eggs.
Eggs are an awesome source of protein and there are hundreds of uses for them but they've become expensive the past three or four years. I have a couple dozen hens and two roosters and share eggs with my daughter and her family across the road from us.
I eat them every morning, come hell or high water. I don't mind eating them any time of day. My grandsons (8 and 6) would eat scrambled eggs five times a day and never whine.
I boil a couple dozen every weekend, peel them and have them in the fridge for snacks all week. I can eat three of them with all sorts of mustards and condiments and feel like I've had lunch.
My dad was pretty old when I was born so I heard all the first-hand depression stories from him and his siblings. They bought flour, sugar and coffee beans at the store. Period. They raised everything else or didn't eat it.
In the 60's and 70's, I never, ever saw my uncle eat anything for supper but a piece of toast and a bowl of white flour gray. He was skinny as a rail, farmed and worked outside into his 80's.
I collect plastic grocery bags from neighbors, often in exchange for eggs. Using classical conditioning, I train my chickens to pass their pre-laying farts into those bags. I carry them to the house and ignite them, one by one, under the skillet to fry the eggs.
Speaking of bags, my aunt on the rich and uppity side of the family never let a bag leave the house. I saw her take the bag out of an empty cereal box, fold it more carefully than a flag at a veteran's funeral and place it a drawer for saving bags. She literally used them over and over, washing them out and turning them inside-out to dry. She liked them because they're so tough.
She unfolded the box and put it in a drawer for the grandkids to cut up and make things out of when they visited.
She wouldn't buy zip-lock type bags because they're hard to wash and reuse. She had a drawer FULL of rubber bands, some of which appeared to be depression-era. She had a drawer for every single thing. There were drawers built into the walls of a hallway from floor to about four feet high with cabinet doors above them. Virtually nothing left her house as trash. She was, as I said, rich and uppity.