Heat oven to 250°F. In 1-quart saucepan, melt butter over medium heat. Remove from heat. Stir in garlic powder, soy sauce and chow mein seasoning mix with wire whisk until well mixed.
In large roasting pan, mix remaining ingredients except wasabi peas. Pour butter mixture over cereal mixture; toss evenly to coat.
Bake 50 to 55 minutes, stirring every 15 minutes, until mixture looks dry and crisp. Pour mixture onto paper towels. Cool 15 minutes. Stir in wasabi peas before serving. Store in tightly covered container.