Preheat oven to 350 degree F. In a large saucepan melt margarine or butter over medium heat. Add bulgur; cook for 2 minutes. Stir in the celery and onion.
Cook and stir 3 minutes more or until vegetables are just tender. Stir in the chicken broth, cooked wild rice, parsley, pepper, and, if using, dried basil and dried oregano.
Bring to boiling; reduce heat. Cover and simmer for 10 minutes. Stir in mushrooms, walnuts, and, if using, fresh basil and oregano. Transfer mixture to a 2-quart casserole. Bake, covered, for 30 minutes or until liquid is absorbed. Makes 8 to 10 servings.