Combine all seasoning ingredients (parsley, chives, dill, onion powder, garlic powder, salt, pepper, celery seed) in a small jar or airtight container
Shake or stir to mix well and store in a cool, dry place
In a bowl or large measuring pitcher, combine mayo, sour cream, kefir, and vinegar and mix
Pour half of that mixture into a quart-size jar, then add the ranch seasoning mix
Stir or shake until smooth, then pour in the rest of the dressing mixture to fill the jar
Refrigerate for at least 30 minutes before serving so the flavors can meld
