In a large pot melt 2 sticks butter in water. When melted add dry cornbread stuffing stirring to incorporate liquid, set aside.
In a large saute pan set over medium-high heat melt 1 tablespoon butter and add sausage. With a wooden spoon break up sausage and saute until lightly browned and cooked through. Transfer sausage to paper towels to drain. In the same pan melt remaining butter and saute onions with the garlic, celery, thyme, and sage until onions are translucent and celery is crisp tender. Add walnuts and saute for 1 minute. Add apples and saute for one minute more. Remove from heat. Combine cornbread stuffing with sauteed ingredients and stuff turkey. Roast turkey as usual.
Alternatively: fill a 10 by 15 by 2 inch pan with the stuffing, moisten with the giblet stock, and bake in a preheated 350 degree F oven, covered with foil for 1/2 hour. Remove foil and bake until top is lightly browned, about 15 minutes more.