Scalloped Potatoes

This is a cross-reference recipe: Mrs. Wilson assumes you already know how to scallop oysters and simply asks you to treat sliced raw potatoes the same way. The technique is layering in a buttered dish with seasoning, thickening and liquid, then baking under a browned top.

• What "scallop" meant hereWhat "scallop" generally meant -- in period usage, alternating thin layers of the main ingredient with flour or fine cracker crumbs, salt, pepper and dots of butter, then enough milk to come nearly level with the top layer. The original gives none of these details; for potatoes, milk rather than butter alone is the practical choice, since they have to cook through in it.
• The hinge: slice thin and evenThe recipe does not say whether the potatoes are raw or parboiled; if raw, they want slicing very thin, on the order of an eighth of an inch, or the top browns before the middle is tender. A mandoline or the slicing side of a box grater is worth the trouble.
• Oven temperatureNone is given. A moderate oven, around 350F, covered for the first 40 minutes so the potatoes steam and then uncovered until the top browns, works in practice; reckon on 60 to 75 minutes for a two-inch-deep dish.
• PimentosThese are sweet red peppers, sold in this period in small cans or jars, roasted and peeled. Drain and chop them, or the packing liquid will thin the sauce; jarred roasted red pepper is the usual modern stand-in, though pimiento is a specific variety.
• The cheeseUnspecified; a firm American or dry Cheddar suits the dish. The recipe says only that it goes on top; adding it for the last 15 minutes uncovered keeps it from going greasy and leathery over a full hour of baking.
• Milk and curdlingWhole milk poured over raw starchy potatoes tends to break at high heat. Keeping the oven at 350F and using the flour or crumb layers as thickener holds it together; scalding the milk first also helps.
• Quantity and yieldNo amounts are given. Two pounds of potatoes, about two cups of milk, two tablespoons flour, a two-ounce jar of pimentos and four ounces of cheese fills a nine-inch dish and serves six as a side.