For the parmesan-peppercorn ranch: Put the mayonnaise, sour cream, Parmesan, parsley, green onions, peppercorns, Worcestershire, vinegar, salt, hot sauce and garlic in a blender or food processor and blend to combine. Add the buttermilk to the desired consistency and blend thoroughly. Chill for 30 minutes to a couple of hours before serving, thinning with more buttermilk if needed.
For the wedge salad: Arrange the lettuce wedges on a white rectangular plate in a straight line slightly overlapping. Drizzle the dressing over the lettuce, add the carrots and sprinkle with the crushed peppercorns.