2) Stir the buttermilk, sour cream, and garlic in a medium bowl to blend; mix two thirds of the cheese. Season the dressing with salt and pepper, to taste. (The dressing can be made up to 2 days ahead. Cover and refrigerate. Stir to blend before using, adding more milk to thin the sauce, if necessary.)
3) Arrange each of six lettuce wedges on sixplates. Spoon the dressing over the lettuce. Sprinkle with the pancetta and remaining cheese and serve.