Heat oven to 450 degrees F. Pour oil into 13 x 9 x 2-inch metal baking pan. Heat oil in oven until very hot, 5 minutes.
In large bowl, mix cornmeal, flour, baking powder, sugar, salt. Stir in eggs, milk. Carefullly pour hot oil into cornmeal mixture; mix. Pour into heated pan.
Bake in 450 degree F oven for 20 to 25 minutes, until golden. Let stand 10 minutes; crumble.
Reduce oven to 350 degrees F. In large skillet, saute onion and celery in 12 tablespoons butter and the olive oil until vegetables are softened, about 7 minutes.
In bowl, mix onion mixture, sage, salt, pepper, bread. Spoon in 13 x 9 x 2-inch glass baking dish. Melt remaining butter; drizzle over top, with stock. Cover with foil.
Bake at 350 degrees F for 20 minutes. Remove foil; bake 10 minutes, until browned. Makes 12 to 14 servings.