1 head lettuce, sliced into 4 wedges
1 cup reduced-fat sour cream
1/4 cup crumbled blue cheese
1 to 2 tablespoons milk
1/4 teaspoon ground black pepper
Arrange lettuce wedges on individual plates.
In a medium bowl, whisk together sour cream, blue cheese, milk, and black pepper (add more milk if necessary to make a thinner dressing).
Spoon dressing over lettuce wedges just before serving.