Scalloped Ham and Potato

A plain milk-baked ham and potato dish that depends almost entirely on slicing and oven temperature. Everything else takes care of itself.

• Slice thin and evenThis is the hinge. The potatoes cook only in the milk and their own steam, so slices thicker than about 1/8 inch will still be firm long after the milk has gone. A mandoline or the slicing side of a box grater gives the uniformity that matters more than speed.
• "Very slowly" means 300-325F"Very slowly" means a slow oven -- books of this period put that somewhere in the 250-325F range, and around 300F is a reasonable reading here. Higher heat boils the milk hard and it can separate into curds and thin whey before the potatoes give way.
• CasseroleIn this era the word generally means the baking dish itself rather than its contents. A 2-quart lidded dish, or any baking dish tightly covered with foil, does the job; the recipe calls for a cover, and that is what keeps the top layer from drying out.
• TimingExpect 1 1/2 to 2 hours covered. Test with a knife tip through the center rather than watching the clock. If you want colour, uncover for the last 20 minutes.
• 1 pt. milkTwo cups. Whole milk holds together better than skim at this temperature; some cooks swap in half a cup of cream for insurance against curdling.
• No salt, and that is deliberateNo salt is called for -- cured ham supplies plenty, though the recipe does not say why it is left out. Taste before adding any, especially if you are using a modern wet-cured supermarket ham, which is saltier and wetter than the drier cured ham this recipe likely assumes.
• The ham"Cut ham into pieces suitable for serving" most likely means slices or chunks off a cured ham rather than thin sandwich ham, which disappears into the milk. Thick-cut ham steak, diced or cut into portions, is the closest common substitute.
• PotatoesSix potatoes is roughly 2 to 2 1/2 lb. A starchy or all-purpose potato thickens the milk slightly as it bakes; waxy ones stay in distinct slices but leave the sauce thin.
• RestingLet it sit 10 minutes out of the oven. The liquid is loose when hot and firms up considerably as it cools.