In a large deep skillet, saute 1/2 pound diced andouille sausage in 6 tablespoons butter for 3 minutes. Season with salt and pepper and add 1 chopped onion, 3 chopped celery stalks and 1 tablespoon each chopped thyme and sage; cook 5 minutes, then add 4 cups sliced collard greens and let wilt. Pour in 3 cups chicken broth. Simmer until step 5. In a large bowl, mix 2 large eggs. Add to the bowl 8 cups toasted white bread cubes, 6 cups crumbled cornbread and the hot broth mixture. Gently toss the stuffing, then spread in a buttered 9-by-13-inch baking dish. Dot the top with butter or turkey pan drippings, cover and bake 30 minutes at 350 degrees F. Uncover and bake until golden, 20 more minutes.