Meat loaf is one of those dishes that can take on so much, like vegetables, leftover mashed potatoes, the end of a bottle of wine from the weekend, a bit of stale bread.
Simple, basic, and infinitely adjustable to one's own palate (by adding beans or asparagus instead of peas, or using cream of potato or celery soup instead of mushroom), and yet just about impossible to improve upon, this Campbell's recipe is the classic tuna casserole.