Is there a recipe for Hidden Valley dressing?

According to the nutrition facts on an Original Ranch Dressing bottle, it contains:

Soybean oil, water, egg yolk, sugar, salt, cultured nonfat buttermilk, natural flavors (soy), spices, and less than 1% of: dried onion, dried garlic, vinegar, phosphoric acid, xanthun gum, modified food starch, monosodium gluntanate, artificial flavors, disodium phosphate, sorbic acid and calcium disodium edta as preservatives, disodium inosidate, and disodium guanylate.