1/4 cup plus 2 tablespoons vegetable shortening
1 cup yellow cornmeal
1/2 cup all-purpose flour
1 tablespoon baking powder
1 teaspoon salt
1/2 teaspoon baking soda
1 cup buttermilk
1/2 cup milk
1 large egg
1 loaf crusty French bread, cut into 1-inch cubes (about 8 cups)
1 stick unsalted butter
4 stalks celery, finely diced (leaves included)
2 carrots, finely diced
1 large onion, diced
4 cups low-sodium chicken broth, plus more if needed
2 teaspoons chopped fresh rosemary
1/2 teaspoon dried thyme
1/4 teaspoon ground sage
1/8 teaspoon turmeric (optional)
1/4 cup chopped fresh parsley
The day before making the stuffing, bake the cornbread: Preheat the oven to 450 degrees F. Melt 2 tablespoons shortening in a 9-inch cast-iron skillet over medium heat. Meanwhile, combine the cornmeal, flour, baking powder, salt and baking soda in a large mixing bowl. In a separate bowl, whisk the buttermilk, milk and egg until combined. Slowly incorporate the wet ingredients into the dry, stirring until combined. Melt the remaining 1/4 cup shortening in the microwave and add to the batter, stirring constantly. Pour the batter into the hot skillet, smoothing the surface with a rubber spatula. Bake until golden brown, 20 to 25 minutes. Let the cornbread cool in the skillet, then cut into 1-inch cubes.
Spread the cornbread and French bread cubes on 2 baking sheets and let dry at room temperature, uncovered, until totally crisp, about 24 hours. Transfer to a large bowl and toss to mix them up a bit.
Make the stuffing: Preheat the oven to 350 degrees F. Melt the butter in a large skillet or Dutch oven over medium heat. Add the celery, carrots and onion and cook until the onion is almost translucent, about 6 minutes. Add the chicken broth and bring to a boil. Reduce the heat to low and add the rosemary, thyme, sage and turmeric. Gradually ladle the broth mixture into the bowl with the bread, tossing gently. Taste as you go and add salt carefully. If the mixture is not moist enough, add a bit more chicken broth. Stir in the parsley.
Transfer the mixture to a 9-by-13-inch baking dish. Bake until golden brown, 20 to 25 minutes. Let rest 10 minutes before serving.