Makes about 2 cups, 8 servings
Make Ahead: The dip can be made up to 2 days ahead, covered and refrigerated. If too thick, thin with milk before serving.

Onion dip (yes, the kind made from powdered onion soup) with potato chips used to be one of my secret passions until I started making this from-scratch version. Feel free to leave out the cheese if you want an unadulterated onion dip experience. Some of you will remember this recipe from my Dips article in Bon Appétit (March 2001). It's worth repeating.

2 tablespoons vegetable oil
1 1/4 cups thinly sliced shallots (about 6 ounces)
3/4 cup mayonnaise
3/4 cup sour cream
4 ounces Roquefort or Danish blue cheese, at room temperature
Salt and freshly ground black pepper, to taste Potato chips, for serving

1. In a heavy-bottomed medium saucepan, heat the oil over medium-low heat. Add the shallots and cover. Cook, stirring often, until the shallots are deep golden brown, about 20 minutes. Cool completely.
2. In a medium bowl, combine the mayonnaise and sour cream. Add the cheese and mash with a rubber spatula until almost smooth. Stir in the cooled shallots and season with the pepper. Cover and refrigerate until chilled, about 2 hours. Serve chilled or at room temperature with potato chips.