Tuna casserole is fairly inexpensive especially if you use store brand products.

A couple of packages of top ramen with some leftover veggies, meats or some hard boiled egg. You can pretty much add all kinds of stuff to "dress it up".

Frijoles Charros is a great recipe for beans and you can adjust the heat by adjusting the spice. Spoon it over rice to stretch it or eat with tortillas. (Homemade tortillas are super cheap to make and soooo much better than store bought!)

Lentil soup is another meal idea.

Buy whole chickens instead of pieces and learn to cut them up. That can save huge amounts of money and you can save the back portions and use those to make chicken noodle soup or stock or chicken and dumplings or whatever.

Shop meat that is marked down because it's close to the sell by date. Make sure you look carefully and reject anything that doesn't look or smell right.

If you don't already cook from scratch, learn if you can. There are a ton of sites online dedicated to budget friendly recipes. Besides it's cheaper, better for you and you can always adjust the recipe to suit your family's preferences.

Check out the sales especially at your local "cheap" stores. Not sure where you are but I love Aldi's, Save-A-Lot and Walmart grocery. They have great sales and your money will go so much further.

Best of luck and hopefully things will get better