Simple, cheap, and something I make so often that it hardly seems worth mentioning... but one of the kids' favorites, so I really should.
It's just steak, broccoli, and mashed sweet potatoes with salt and butter. I usually get Top Sirloin when it's on sale but today I scored some skirt steak in the 50% off bin (I should have bought all of them to freeze! So not thinking!) and grilled it in a skillet with butter and onions, then after steaming the broccoli for 6 minutes I gave it a quick swirl in the amazing pan drippings to season it.
You make mashed sweet potatoes exactly like regular mashed potatoes; I like to mix in a dollop of sour cream when mashing, then serve with butter and salt.
This whole meal cost about seven dollars, and we have leftovers!