Real French Onion Dip | The Food Lab

Heat sugar in a 12-inch stainless-steel skillet over medium-high heat until completely melted and light brown, about 3 minutes. Immediately add onions and stir with wooden spoon to coat onions in sugar. Add butter, salt, and black pepper. Stir  to combine. Cook, shaking pan occasionally until onions release all their liquid and brown coating builds up on bottom of pan, 6 to 8 minutes.

Add 2 tablespoons water shake pan while scraping with wooden spoon to deglaze brown bits from bottom of pan. Continue cooking, shaking occasionally until coating begins to build up again, about every 2 minutes. Repeat deglazing and cooking steps three more times until all water is used up and onions are deep brown. Transfer to medium mixing bowl and allow to cool at room temperature for 10 minutes.

Add sour cream, mayonnaise, lemon juice, parmesan, and Worcestershire and whisk to combine. For a smoother texture, run through blender or food processor for 1 minute until smooth. Chill in a sealed container for at least 1 hour and up to 5 days (flavor will improve with time). Spoon into a bowl, sprinkle with chives, and serve with potato chips.