Make the dressing by combining all the dressing ingredients except for the milk and stirring with a fork until well combined (some chunks of blue cheese are good – it shouldn’t be totally smooth). Thin it with just enough milk that it is still thick but pourable.
Peel the outside 1 or 2 leaves off of the lettuce and cut it into quarters lengthwise (from core to top) so you have 4 wedges. Carefully cut the core part out of the end of each wedge, and place each wedge on a plate.
Generously drizzle the dressing on top of each wedge. Divide the tomatoes and bacon around each wedge. Sprinkle each with chives and a grinding of pepper, and scatter a few cheese crumbles on and around each wedge. Serve at once.