Root Vegetable Gratin is a tasty side dish for Thanksgiving
The side dishes on our annual Thanksgiving menu almost always include mashed potatoes and roasted root vegetables. This year I decided to change up the routine by combining the two, adding a little cream and topping off the hybrid with some crunch. It's heartier that way and tastier, too.
This recipe calls for a pound of turnips and one-half pound each of carrots and parsnips. What if you're not a fan of turnips? (Some folks find them a bit funky.) Just leave them out and increase the amount of carrots and parsnips. But try not to mess with the specified amount of potatoes. It's their starch that thickens the sauce.
The dairy is a combination of cream and milk (the latter lightens the dish) infused with garlic, thyme and bay leaf. Seasoning a gratin is usually hit or miss - you sprinkle some salt willy-nilly on top of the raw vegetables as you layer them into the baking pan. Here we call for an exact measure of salt to be added to and dissolved into the cream/milk mixture. That way the seasoning is perfect.
It's important to make sure the vegetables are sliced thinly and evenly so that they all become tender at the same time. You can do it by hand, but you will get more uniform results with a mandoline or the slicing disk of your food processor. (If you do choose to work with the mandoline, be sure to put the guard into place.)
One final note - not all baking pans perform the same way in the oven. When I made this dish in a metal pan, the vegetables were tender in 40 minutes. When I used a glazed earthenware pan, they took more than 50 minutes. The difference speaks to the relative ability of each material to conduct - or resist - heat. In either case, it's crucial to keep an eye on the process.
• Sara Moulton is host of public television's "Sara's Weeknight Meals." She was executive chef at Gourmet magazine for nearly 25 years and spent a decade hosting several Food Network shows, including "Cooking Live." Her latest cookbook is "HomeCooking 101."