Heat oven to 250ºF. In 13 x 9-inch baking pan, combine cereal, chow mein noodles and cashews; mix well. In small bowl, combine oil, soy sauce, garlic powder and onion powder; blend well. Quickly pour over cereal mixture; stir to coat evenly. Bake 1 hour, stirring every 15 minutes. Transfer to baking sheet, spreading mixture in even layer. Cool completely. Makes about 10 cups (20 1/2 cup servings). Store tightly covered.