One of my mother's favorite dishes, this recipe always brings back fond memories of her when I prepare it. It's a terrific use of leftover ham from a holiday dinner. Our five grandchildren are my favorite interest outside the kitchen!
One of my mother's favorite dishes, this recipe always brings back fond memories of her when I prepare it. It's a terrific use of leftover ham from a holiday dinner. Our five grandchildren are my favorite interest outside the kitchen!
Starch control is paramount when combining potatoes, dairy, and a roux-based sauce in a single baking dish. Potatoes boiled whole or in large chunks release less free starch into the boiling water, preventing a gummy interior before the casserole ever hits the oven. Cut potatoes and root vegetables uniformly to 1/2-inch cubes so thermal energy penetrates each piece simultaneously during the 15-minute boil.
A heavy-bottomed 2-quart saucepan distributes heat evenly when building the béchamel base, protecting the flour and butter paste from scorching while the milk reaches its thickening threshold. Whisk cold milk into the hot roux gradually to eliminate lumps, maintaining a vigorous motion for the full two minutes of boiling required to cook out raw starch flavors. Shred sharp cheddar cheese on the fine side of a box grater rather than using pre-packaged shreds, which are coated in cellulose that prevents smooth emulsification.
Bake this dish uncovered at 375 degrees Fahrenheit for 25 to 30 minutes. Uncovered baking allows excess moisture to evaporate, which keeps the bread crumb topping crisp and prevents the sauce from breaking into an oily separation. Swap whole milk for half-and-half if a richer mouthfeel is desired without altering the flour-to-fat ratio.