A holiday dinner is your chance to pull out all the stops. See Crown Roast of Pork 101 for step-by-step instructions on making this majestic centerpiece.
Place pork racks, fat side down, on a work surface. Cut a third of the way through flesh between each rib bone. This will allow racks to fan open into a crown shape (see step 3).
Position racks as shown, fat sides touching and bones upright. Thread a trussing needle with cotton kitchen twine and horizontally run it through meat just below last rib bone on 1 rack and straight through meat of opposite chop.
Tie chops together as tightly as possible to form a half circle, or half of the crown. Then repeat process on other end of racks to finish the crown. (You can also use this technique on racks of lamb.)
Where racks are joined, tie rib bones together. At this point, you can store the crown roast, uncovered, in the refrigerator 1 day. Bring to room temperature before continuing, about 1 hour.
Preheat oven to 425 degrees with rack in lower third. Place roast on a flat rack set in a roasting pan; season with salt. Stir together garlic, sage, orange zest, oil, and 1/2 teaspoon pepper; spread all over roast. Let stand 30 minutes; prepare stuffing.
Fill with 6 cups stuffing; roast 30 minutes. (Tent with foil once stuffing browns.) Reduce heat to 375 degrees; roast until a thermometer inserted down between bones into thickest part of flesh reaches 140 degrees, 1 hour. Transfer to a board; let rest 20 minutes.
Melt butter in a skillet over medium-high heat. Saute onion and celery with salt until translucent, 3 minutes. Add sage and wine; boil to reduce by half, 2 minutes. Toss with bread, chestnuts, parsley, broth, and juice. Fold in eggs. Stuff crown with about 6 cups (see step 6); roast. While cooked roast rests, bake remaining stuffing at 375 degrees in a buttered baking dish until brown, 20 minutes.
Tilt roasting pan; skim fat from drippings. Place pan across 2 burners over medium-high heat. Add wine and bring to a boil, scraping up browned bits. Add 1 1/4 cups broth; return to a boil. Whisk together remaining 1/4 cup broth and flour, and pour into pan, whisking, until thickened slightly, about 1 minute. Remove from heat, stir in butter and accumulated juices from roast, and strain.
After the crown roast has rested, transfer to a serving platter. Remove all twine. Garnish with sage and kumquats. Use a carving knife to cut roast between each rib for individual chops, and serve with stuffing and gravy. Store any remaining crown roast whole (sliced chops dry out faster) in refrigerator up to 3 days.
Eight-chop racks of pork for a crown roast aren't a standard supermarket item, so order them several days ahead of time. Ask the butcher to remove the chine bone, trim excess fat, and french (clean) the bones.