In work bowl fitted with metal blade, process cream cheese, cottage cheese, buttermilk, dill, onion flakes, pepper and salt until smooth, about 2 minutes.
It's best to let flavors mingle by chilling in the fridge for a couple hours, but you can enjoy it immediately if you choose.
Notes
You can use dried dill instead of fresh, but I highly recommend getting the fresh variety. The flavor is just so much better.
While this dill dressing is great on salads, you can also serve it with fried fish, or put in a bowl surrounded by fresh veggies for a great dill dip!