For some who stumbled here looking for the "mystery onion dip", here is my attempt.

Mysteryonion’s "My Mystery Onion Dip"

2 onions medium size finely chopped (roasted or fried and then chopped fine)

1 pint sour cream

1 clove garlic (optional)

2 Tablespoon yellow mustard

½ teaspoon salt
2 or 3 pinches of smoked Paprika

2 Tablespoon fine chopped Celery

2 teaspoon fine chopped Cilantro

1 Tablespoon white sherry

 So what is the mystery?  I left out the onion soup mix...shhh... don't tell anyone.