1. Preheat oven to 325ºF and line a large rimmed baking sheet with parchment. Whisk together egg white, Worcestershire sauce, sugar, chili powder and salt in a large bowl. Add popcorn, pretzels and peanuts and toss to coat.
2. Spread mixture on baking sheet and bake until crisp, about 20 minutes, stirring once or twice during baking time. Set baking sheet on a wire rack until mixture has cooled completely.