I worked at a steak house that made their own Ranch dressing without mix. We ground yellow onion, celery, garlic and a little parsley through a Hobart attached food grinder. Mayo, buttermilk, pepper and salt. I think its the pureed celery/buttermilk combo that gives it that distinctive "Ranch" flavor. Since I don't write down recipes, you will have to play with it a little. You could also try TSR for the Hidden Valley recipe. Good luck and Merry Christmas.