Preheat oven 350 F. *if the oven is on, it's fine to cook this stuffing at whatever temperature is needed for the turkey or other dishes.
Coat a 9 X 13 inch baking or casserole dish with cooking spray.
In a large skillet over medium-high, heat 2 tablesoons of the butter until it melts. Add the onion, celery, bell pepper, mushrooms and garlic. Saute until the onions start to brown, about 7 to 8 minutes.
Stir in the garlic powder and thyme, then heat for another minute. Add the remaining 6 tablespoons of butter and stir until melted
Transfer the vegetable mixture to a large bowl, scraping the pan. Add the cashews, rosemary, orange zest, salt and pepper. Stir well, then mix in the stuffing mix.
In a second bowl, whisk togehter the broth and egg, then drizzle over the stuffing mixture. Mix very well, then spoon the mixture into the prepared baking or casserole dish.
Bake for 30 minutes, or until browned on top and 165 F at center
Nutrition information per serving (values are rounded to the nearest whole number):430 calories;200 calories from fat (36 precent of total calories); 22 g fat (9 g saturated; 0 g trans fats); 60 mg cholesterol; 47 g carbohydrate; 11 g protein; 5g fiber; 940 mg sodium.