How to Make It
Place beans, cheese, sour cream, and lemon juice in a food processor; process until completely smooth.
Heat oil in a medium saucepan over medium. Add leek; cook until softened, 5 to 7 minutes. Add flour; cook, stirring constantly, 1 minute. Add stock; cook, stirring constantly, until thickened slightly, 1 to 2 minutes. Reduce heat to medium-low. Add bean mixture; cook, whisking constantly, until heated through, 1 to 2 minutes. Remove from heat; stir in salt and pepper. Transfer to a serving bowl. Sprinkle with chives; serve immediately with vegetable chips.