Mom's specialty, episode II

364 days a year Mom’s culinary specialty is her Lasagna with Spinach and Cottage Cheese. But every year on Thanksgiving, Mom’s contribution is her special “yam-apple casserole.” The recipe calls for cooked chestnuts to be sprinkled over the sweet potatoes and apples before baking, but she never does that because it’s hard to find the chestnuts. This year, I saw Trader Joe's Peeled & Cooked Chestnuts the week before Thanksgiving, but they were nowhere to be found the week of Thanksgiving. When I went to do my regular Trader Joe’s shopping trip this week though, the chestnuts were back. So I picked up a package, and we had a special treat when Mom made her other specialty for us the second time in 10 days, this time with chestnuts. Now it’s only about 350 more days until we can have it again.

Rum-Glazed Sweet Potato, Apple, and Chestnut Gratin

Adapted from Gourmet Magazine

3 pounds sweet potatoes, pricked several times with a skewer
3 Golden Delicious apples, peeled and cut lengthwise into eighths
¼ cup fresh lemon juice
1 cup (5¼ ounces; 150 grams) vacuum-packed roasted chestnuts, halved (can substitute pecans)
6 tablespoons (3 ounces; 85 grams) unsalted butter
½ cup (3½ ounces; 100 grams) packed light brown sugar
½ cup (6 ounces; 170 grams) honey
2 tablespoons dark rum
½ teaspoon cinnamon
¼ teaspoon ground ginger
¼ teaspoon ground mace

    1. Place rack in center of oven. Heat oven to 400 degrees. Grease a 14-inch gratin dish or 13-by-9-inch lasagna pan.
    2. Bake the sweet potatoes, on top of a piece of aluminum foil, until tender, 45–60 minutes. Let them cool. Peel potatoes and cut them diagonally into ¼-inch slices.
    3. In a medium bowl, toss the apples with the lemon juice, then arrange them neatly in the prepared pan with the sweet potato slices. Sprinkle with the chestnuts (or pecans).
    4. In a small saucepan, cook the remaining ingredients over moderate heat, stirring occasionally, until the sugar is dissolved. Spoon the mixture over the sweet potatoes and apples.
    5. Bake the gratin, basting occasionally, until the apples are just tender and the sweet potatoes are heated through, about 30 minutes. (The uncooked gratin can be assembled 1 day ahead and kept, covered, in the fridge. Bake, uncovered, basting occasionally, for about 40 minutes.)
    6. Put the gratin under a preheated broiler about 4 inches from the heat until the edges are browned lightly. Serves 8.