I would need to do a lot of adjusting for being made over a fire and do a whole lot of temperature, time, pot used, and ingredient amount/type used, but I could provide a cheesy tuna noodle casserole recipe.

Obviously this restarted civilization probably wouldn't have canned goods, an oven, a stove, a 9x13 glass pan, a clock for timing, and spray oil, so I would have to adjust the recipe to account for all of that before submitting it for that type of book.

Though, what I assume would be the hardest ingredient to come by would definitely be the cream of mushroom and cream of chicken.

Edit:

Looked up what exactly goes into cream of mushroom and it still probably would be the hardest to get due to the diversity of ingredients depending on the recipe.