This is the best for cooking for one; few ingredients, easy, cheap (so cheap!), somewhat healthy, not that much washing up. I’ll give quantities to feed one, but can just increase for however many you want.
Here's a cheap and easy recipe for zucchini from reader Brigitta Patterson.
Here's a cheap and easy recipe for plantains by reader Desiree Fields. I bet you can get all these ingredients at your local not-Whole Foods market for $7 (not including oil, spices, or vinegar).