Brussels Sprouts & Chestnuts
Using a sharp knife, score a cross on the flat side of each chestnut. Dip chestnuts, 4 or 5 at a time, into a saucepan of boiling water. Using a slotted spoon, remove chestnuts and peel away shells and inner brown skins. Place the peeled chestnuts in a large saucepan and add enough boiling water to cover. Add celery stalk and simmer, covered, for 30 to 45 minutes, or until tender. Drain, discarding celery, and refresh with cold water. Set aside.
With a vegetable peeler, remove the zest from half the lemon. (Save lemon for another use.) Cut the zest into julienne strips and place in a small saucepan; cover with cold water and bring to a boil. Drain and set aside.
With a paring knife, cut a small cross, 1/8 inch deep, in the stem end of each Brussels sprout. Bring a large saucepan of salted water to a boil. Add the Brussels sprouts and cook, uncovered, until tender, 6 to 8 minutes. Drain and refresh with cold water. (The vegetables can be prepared ahead and stored, covered, in the refrigerator for up to 8 hours.)
In a large skillet, heat broth and butter. Add the chestnuts and Brussels sprouts and toss over medium heat until heated through. Season with salt and pepper and garnish with the julienned lemon zest.