Whisk all ingredients together. For a more finely-ground mix, pulse the mixture in a food processor or high-power blender. Store in an airtight container in the refrigerator for up to 3 months.
To Make Ranch Dressing: Whisk together 1 tablespoon of seasoning mix, 1/3 cup mayonnaise or plain Greek yogurt, and about 1/4 cup milk. Add more or less milk until the dressing reaches your desired consistency.