Preheat your oven to 250°F (120°C).
In a large mixing bowl, combine the Corn Chex, Rice Chex, pretzel sticks, and mixed nuts.
In a separate bowl, whisk together the dill pickle seasoning, olive oil, garlic powder, onion powder, and black pepper until combined.
Pour the seasoning mixture over the Chex mix and toss to coat thoroughly.
Spread the mixture evenly on a large baking sheet.
Bake in the preheated oven for 1 hour, stirring every 15 minutes.
Remove from the oven and let it cool completely before serving.
