My favorite cheap meal is actually a little market-dependent, but great when sales roll around. When roasting chickens dip below $,79/#, I get a couple. Freeze one, roast another. Have roast chicken (side of frozen mixed veg & mashed potatoes) for one meal, some kind of chicken casserole with two cups of shredded leftover meat for another, then soup with the bones & scraps of leftover meat, plus loads of stock for later.

Probably doesn't work for picky, wanna-be-a-vegetarian Delia, I'm afraid--I didn't think about that until just now.