How to Make It
Heat a grill pan over medium-high. Rub chicken thighs with 1 tablespoon oil, 1¼ teaspoons salt, and 1 teaspoon pepper. Toss baby bell peppers with remaining 1 tablespoon oil. Grill chicken and peppers in hot grill pan, turning occasionally, until cooked through and charred, 8 to 10 minutes. Remove from heat; slice chicken.
Chop 1 cucumber and mix with buttermilk, sour cream, lemon juice, 1 tablespoon dill, and remaining ¾ teaspoon salt and ￼¼ teaspoon pepper in a small bowl. Divide lettuce among 4 plates; top evenly with grilled chicken and peppers. Slice remaining cucumber and add to salads. Drizzle with dressing, top with pita chips, and sprinkle with remaining 1 tablespoon dill.