Place mayonnaise, mustard, Worcestershire, vinegar, onion, garlic, anchovies, chipotle, hot sauce, honey and salt and pepper in a blender and blend until smooth. With the motor running, slowly add the oil and blend until emulsified. Add the Parmesan and blend a few seconds longer.
Heat grill to high.
Brush romaine with oil and season with salt and pepper; place on the grill cut-side down and grill for 30 to 40 seconds or until slightly charred. Arrange lettuce on large platter, drizzle with the dressing and garnish with shaved Parmesan.