First thing that comes to mind are bean burritos. Cheap, quick and easy. Flour tortillas, shredded cheese ( I prefer cheddar or Monterey Jack), can of Vegetarian refried beans. In addition, you can add Chopped tomato, olives, onions, lettuce , hit peppers, salsa, guacamole.
With some of the same ingredients, pan fried quesadilla ( cheese , bean or bean and cheese).
If you're OK with Vegetarian meat, you could get the Morning Star Crumblers ( basically vegetarian chopped meat). Cook it up as instructed, add packet of taco seasoning and load up some taco shells with it and the above ingredients . What I actually usually do , is make a taco salad ( lettuce, olives, tomatoes , onions , shredded cheese and the taco meat). Mix it all up and just load the taco shells with that and top it off with guac.
If you can swing some time to make Eggplant Parmesan, it could be 3 different dinners. Night one Eggplant Parm, night 2 Eggplant parm hero, night 3 Eggplant parm on top of baked ziti ( a local restaurant used to serve it like that and call it Baked Ziti Sicilian. Not sur if its an authentic name for an authentic dish, but it tasted good).
Cheese Hoagies ( back from my Philly days) Roll ( I prefer Keiser rolls) Spread mayo, a couple of slices of provolone, pickles, onions, tomato, Hot peppers, lettuce . Drizzle some Italian dressing ( I prefer Good Seasons). Nice quick easy meal
I also like avocado sandwiches. Before Avocado toast was the in thing, We used to make these sandwiches. As simple as keiser roll, mash up and spread avocado on the bread, salt and pepper , finely diced onions, and although I done eat eggs, my friend from El Salvador used too crumble a hard boiled egg on top.
We often have soup and salad nights ( with some bread, although im supposed to watch my carbs). Soup can take long to make, but once made, you can freeze it in batches and have it multiple times with the only effort being defrosting and heating up.
Chili could also be made with the Morning star farm crumblers ( along with sloppy Joe for anything that requires chopped meat).