1. Heat oil in Dutch oven over medium heat. Add onions and thyme, season with salt (if desired), and reduce heat to medium-low. Cook 30 minutes, or until deep brown, stirring occasionally.
2. Stir in 2 cups water, and increase heat to medium. Simmer 10 minutes.
3. Pour onion mixture over bread cubes in bowl, and stir until liquid is absorbed. Stir in pecans, and season generously with freshly ground black pepper.
4. Preheat oven to 350°F. Coat 11- x 7-inch baking dish with cooking spray. Spread stuffing in prepared baking dish, and bake 30 to 45 minutes, or until crisp and brown on top. Cool 5 minutes before serving.