Macaroni and cheese with ground turkey. Brown the turkey while you boil pasta, make a quick bechamel, add cheese.
Tacos. Brown some ground beef, add some taco seasoning (Pensey's Bold Taco Seasoning is my go-to, do a quick corn starch slurry to make a sauce. Serve on soft corn tortillas with cheese, salsa, sour cream (or whatever).
A burrito with some sort of meat and beans. Really depends what I have on hand, but fish chicken or beef all work. Canned black beans or refried beans are easy to use as filler.
I buy some frozen fish patties from Costco and just make sandwiches. Not really much to it than baking it and defrosting a bun.
Fettuccini Alfredo. Butter, cream, and cheese. Throw it over pasta. A tiny pinch of sodium citrate will keep it from separating too. Don't use too much, it makes the texture weird.
I keep ingredients for these things on hand most of the time. I keep a lot of things in my freezer for that purpose. Meat, cheese, homemade burger buns.
Just a note that these are all things that can be made with 15 minutes or less. I don't really keep fully prepared food around.