This casserole makes a quick, well-balanced meal with things you have on hand! If you don't have spinach you can substitute it for a vegetable you do have!
I used to live off of these when I was low carbing. They freeze really well. I also occasionally mixed in TVP (texturized vegetable protein) and flax for some extra fiber.
Slicing carrots with a vegetable peeler transforms them into pasta-like ribbons. Cook them with peas and a pat of butter for unexpectedly luscious results.