2 large yellow onions, cut in half and sliced very thinly
3 tablespoons unsalted butter
1 tablespoon olive oil
Freshly ground pepper
Cayenne pepper (optional)
4 ounces cream cheese, at room temperature
1/2 cup sour cream
1/2 cup mayonnaise
Chives, finely chopped, for garnish (optional)
Heat butter and olive oil in saute pan over medium/medium-low heat. Add onions and season very generously with Kosher salt. Sprinkle with freshly ground pepper and a little bit of cayenne pepper (if using). Cook onions slowly, stirring occasionally, until onions have wilted greatly and have turned a caramelized golden brown, about 35-45 minutes. Depending upon how hot your stovetop is, this time could vary.
Allow onions to cool. Mix cream cheese, sour cream, mayo, and caramelized onions in a bowl with an electric mixer fitted with the paddle attachment (I use my Kitchen-Aid stand mixer) until fully combined. You could probably mix by hand if needed. Taste and adjust seasonings as needed.
Serve immediately at room temperature. If making ahead, refrigerate until about 20 minutes before ready to serve (to allow for mixture to soften and come to room temperature). Serve with potato chips or vegetable crudites…. but really potato chips.