Leftovers can be both a bane and a wondrous thing. Last night, they were wondrous. I had a bit of a zucchini-onion-cheese filling left, mixed it with an egg, and created a delicous main dish in just a few minutes. Crisp corn tortillas, well toasted, filled with tender sweet zucchini and springy egg bridged with a little melting cheese was nearly perfect.
Also, I was very hungry.
Zucchini Egg Quesdilla
Being based on some of the leftover zucchini-onion-cheese blend, I have no precise measurements. To replicate, I would cook a little grated onion until transluscent; add some salted shredded zucchini (allow it to drain for a bit before using), a bit of minced garlic, a pinch of oregano; and cook until the zucchini is tender. Next I’d allow it to cool, and mix with an egg and shredded mozzarella/parmesan/etc. Finally, I’d fill with the egg-zucchini mixture and cook for about 3 minutes per side, or until the egg is fully cooked and the tortillas are toasted.
Sustainable Cooking for One 
It’s a rare occasion that I don’t think leftovers are wondrous.