What are your go-to inflation budget recipes?

There was a contest about 10 years ago— your best dirt cheap dinner. Here are the recipes:
https://food52.com/contests/239_your_best_dirt_cheap_dinner

I eat some form of beans mostly everyday. Beans on toast, tacos, salads, etc. Very economical. Soups stretch $$$ also.

Most any recipe that relies on a grain base (pasta, rice, farro, bulgar, etc.) with vegetables and either eliminates meat or uses it sparingly (like some Asian and Indian dishes) will help the budget. On the other hand, a recipe that cooks a large cut of meat, thinking whole chicken/turkey or chuck pot roast, can do double or triple duty for later meals. I save a roasted bird carcass when picked fairly clean to make chicken/turkey broth for soup. Do a bit of weekly homework and read through the grocery circulars and learn how to spot a bargain on basic foods. Finally, as you walk the grocery aisles, watch for staples and frequently-bought foods that have been marked down. Just yesterday, I found 1# boxes of Domino light brown sugar marked down to 3/$1.00 and cartons of 6 eggs that were near their expiration date for $.83.

Belly - what a good question!
See older cookbooks (e.g., earlier editions of Joy of Cooking) and see/search online for recipes from USA Depression era & UK World War II.
Some recipes from those times that I make - tomato soup cake (eggless, so cheaper), various corn, bean and soup dishes, a vegetable pie as main dish from UK ministry of food during WW2.
Also, for reading to keep the spirits up and make some good food even in hard times, How to Cook a Wolf by MFK Fisher.
https://www.goodreads.com/book/show/250693.How_to_Cook_a_Wolf