Now and again all a recipe requires to embitter a child is one fatal ingredient. My siblings tell me that they recall Hamburger Pie as a kid-friendly favorite. I dreaded it. Spying its mashed-potato crust through the oven window, I always groaned. Today my stomach still sinks with recollection, and here's why: sliced green beans from a can. Yes, they're fast, but can anyone defend the taste, texture, or color of canned green beans? My sister has tried to gussy up this dish, and I'm sure you can find many hoity-toity versions (usually called Shepherd's Pie). But here, taken from the brittle pages of her kitchen scrapbook, is the very recipe my mom prepared for her ungrateful son. Everything in it could be found in our house on any day. Mothers take note: This recipe would allow fresh green beans, cooked. Unless, of course, your little epicure insists on canned!