Place mushrooms in a large roasting pan. Bake at 425° for 20 minutes; set aside.
Meanwhile, combine 2/3 cup oil and flour in a large skillet; cook over medium-high heat, whisking constantly, until roux is dark golden brown (about 15 minutes). Remove from heat, and set aside.
Heat 3 tablespoons oil in a large Dutch oven over medium-high heat. Sauté onion and next 3 ingredients in hot oil 20 minutes or until tender. Add roux, and stir well.
Stir in roasted mushrooms, bay leaves, and next 7 ingredients; bring to a boil. Reduce heat to low, and simmer, uncovered, 1 hour. Stir in green onions, and serve over hot cooked rice.