Slice onions thinly and cook them on low in olive oil. Stir occasionally and sprinkle salt. During the last minute, add garlic and cook until fragrant.
Boil a large pot of salted water and cook farfalle pasta according to package directions. Drain and allow it to cool slightly before combining with the dressing.
In a bowl, mix sour cream, mayo, white wine vinegar, parsley, and soy sauce. Adjust thickness with cooled pasta water if needed. Taste and tweak until perfectly balanced.
Fold the pasta into the dressing gently. Save some caramelized onions for topping. Mix well so every piece is coated without mashing the pasta.
Top with remaining onions, chives, parsley, and a crack of black pepper. Enjoy chilled or at room temperature.