Spinach-Stuffed Quinces

Place quinces in a large saucepan—a pan big enough for quinces to fit in one layer on the bottom—then add stock, thyme, bay leaf, and peppercorns. Bring to a simmer over medium-high heat, reduce heat to medium-low, cover, and poach, turning occasionally, until tender, about 45 minutes. Allow quinces to cool in poaching liquid.

Toast almonds in a small skillet over medium heat, stirring occasionally, until lightly browned, about 5 minutes.

Trim spinach, wash in several changes of water, pat dry, then coarsely chop. Melt butter in a large skillet over medium-low heat. Add onions and cook until soft, about 15 minutes. Increase heat to medium-high, add spinach, and cook, stirring, until spinach wilts, 3–5 minutes. Stir in almonds and nutmeg, and season to taste with salt and pepper.

Preheat oven to 350°. Remove quinces from poaching liquid. Reduce liquid over high heat until concentrated, about 30 minutes. Meanwhile, slice about 1" off the top of each quince and enough off the bottom so that quinces stand upright. Remove cores and hollow out quinces with a paring knife to make shells, about 1⁄2" thick. Chop quince pulp, then add to spinach.

Spoon spinach mixture into quince shells, then place in an ovenproof dish. Strain reduced liquid and drizzle on top. Bake until heated through, 15–20 minutes. Serve warm.