To a very large microwave-safe bowl, add the corn Chex, rice Chex, pretzels, pita chips (I crush them in my hands), and stir to combine; set aside.
To a glass measuring cup or small bowl, add the oil, pickle juice, dried dill, and stir to combine.
Evenly pour the wet over the dry ingredients; stir well to combine.
Evenly sprinkle the ranch mix; stir well to combine.
Cook in the microwave on high power for 5 minutes. Stop every minute to stir well, scraping the sides of the bowl with a spatula if necessary.
Turn mixture out onto a large baking sheet to cool. My mixture was quite dry after the five 1-minute cycles in the microwave but if yours isn’t, it will dry out as time passes if exposed to air.
Notes
Mix will keep for up to 1 week in an airtight container.