1. Preheat oven to 300 degrees F. Line a rimmed baking sheet with parchment paper.
2. Combine the cereal, pretzels, chips, and peanuts in a large bowl.
3. Whisk together the oil, honey, ground mustard, onion powder, and salt.
4. Pour over the cereal mixture and stir to thoroughly coat. Spread evenly on the baking sheet.
5. Bake, stirring every 10 minutes, until the mixture is light golden-brown and toasted (30-35 minutes). Cool before serving and store in an airtight container.