First, preheat your oven to 250 degrees Fahrenheit.
Next, melt the 1 cup of butter in a fry pan over low/medium heat.
Once melted, remove from the heat and add the 1/2 cup wostershire sauce, 2 tablespoons season salt, 3 teaspoons garlic powder, and 2 teaspoons onion powder. Whisk until combined and set to the side.
Pour the seasoned butter mixture evenly over the 2 baking sheets of dry ingredients.
Thoroughly stir the mixture to ensure an even coat over the dry ingredients.
Bake the chex mix for 75 minutes or until fully dry, stirring every 15 minutes. At each 15 minute interval, rotate the 2 pans between the lower and middle oven rack for even baking.
Finally, place 2 large clean hand towels on your counter and spread the chex mix evenly in a single layer to dry more for approximately 1-2 hours.
Enjoy and keep sealed in a airtight food storage container for up to a week.