Directions

1. Preheat oven to 350 degrees. Melt 5 tablespoons butter in a skillet. Toss with bread cubes in a large bowl. Spread in a single layer on 2 rimmed baking sheets. Toast in oven, tossing once, until golden, about 20 minutes. Let cool completely.
2. Place celery root in a medium saucepan; add salted cold water to cover. Bring to a boil; reduce heat, and simmer until soft, about 15 minutes. Drain; set aside.
3. Heat oil and remaining 2 tablespoons butter in a large skillet over medium-high heat until butter has melted. Add celery, onions, garlic, and a pinch of salt; cook, stirring occasionally, until golden brown and soft, about 20 minutes.
4. Put celery root, vegetable mixture, and toasted bread into a bowl. Return skillet to medium heat. Add vermouth; cook, scraping up browned bits with a wooden spoon, until it bubbles. Pour over bread-vegetable mixture. Stir in 1/2 cup stock, the poultry seasoning, and herbs; season with salt and pepper. Stir in 3 eggs.
5. To cook stuffing in turkey, place turkey breast side down, and fill neck cavity with stuffing; avoid packing tightly. Close up by folding skin over and fastening with skewers or trussing needles, if necessary. Turn turkey breast side up; bend wing tips forward and underneath neck cavity so they stay in place (you may have to break wings at joint). Loosely fill large cavity. Using cotton kitchen twine, tie legs together securely (they will overlap) so bird retains its shape and moisture during roasting.
6. For the remaining stuffing, stir in 3/4 cup stock, spoon into a buttered 8-inch square baking dish, and dot generously with butter. Cover with foil, and bake in a 375 degrees.oven for 25 minutes. Uncover, and bake until golden brown, 10 to 15 minutes more. To bake all of the stuffing in the oven; stir an egg and 1 1/4 cups stock into stuffing, spoon into a buttered 13-by-9-inch baking dish, and dot generously with butter. Bake as directed above.