My mom has never been a gourmet cook (she's usually the one to bring the relish tray for family potluck dinners). But she's always been remarkably creative and frugal. A great example of this is the tortilla pizza, a staple of my childhood.
Simple, cheap, and quick, albeit not the most nutritious, this remains a favorite lunch of mine. Now that I have a toaster oven it's ready in record time.
1 flour tortilla
cheese (works best with shredded, but even sliced can be used)
Construct pizza in the usual way. Bake at 350 for 15 minutes.