Pretty much every time I cook, about halfway through the process it suddenly occurs to me that, hey, I could blanche some spinach and throw it in here. It works for almost any dish: omelet, casserole, soup, chili, curry, pasta, or tortilla dish. Blanching is
easy and spinach is one of the most nutritious foods ever. You can reduce several handfuls of spinach:

to a tiny quantity of cooked spinach:

so that you can incorporate extra nutrients into almost any meal with very little effect on its color, texture or taste.
Also, if you fail to eat spinach fast enough and it gets crushed and starts to rot, you don't have to throw it away; just blanche it and mix it in, and it retains its palatibility.