Sweet Potatoes with Apple

A straightforward casserole of mashed sweet potato under a layer of syrup-poached apple. The original gives no quantities, so treat it as a method rather than a formula.

• Working quantitiesAbout 2 lb sweet potatoes, boiled or baked and mashed, fills a 2-quart dish and serves six. Three or four firm apples give an even single layer on top.
• Seasoning the potatoes"Seasoned" here is left to the cook; butter and salt, and perhaps a little cream or milk, would be the usual reading. Salt matters more than sugar, since the apples and the topping supply the sweetness.
• The syrupA light poaching syrup of roughly 1 cup water to 1/2 cup sugar is enough. Simmer the slices only until they yield to a knife tip but still hold their shape, five to eight minutes; fully soft apples collapse into the potato.
• Drain the applesLift the slices out with a slotted spoon and let them drain. Syrup carried into the dish makes the top layer soupy rather than browned.
• Oven425F as given is correct for this dish, on an upper rack. It is a browning bake, not a cooking bake -- everything in the dish is already cooked.
• TimingFifteen to twenty-five minutes, judged by eye. Watch the last few minutes, as the sugar topping goes from caramel to burnt quickly at this heat.
• Sugar toppingBrown sugar gives more colour and a faint molasses note; white sugar sets into a thinner, glassier crust. A tablespoon or two is plenty; the recipe calls for sugar alone, though dotting with butter is a common modern addition.
• Apple choiceA firm cooking variety that holds together in syrup, such as Granny Smith or a Northern Spy, works better than a soft eating apple.