1.
In a large bowl, mix lime juice, oil, mustard, vinegar, cilantro, garlic, sugar,and cumin. Add romaine and lift with 2 forks to coat with dressing. With a slotted spoon, transfer lettuce equally to individual wide bowls.
2.
Add shellfish to dressing in bowl and mix gently. Spoon an equal amount of shellfish and dressing onto lettuce in each bowl, arranging in a 2- inch wide band across the center.
3.
Arrange equal bands of tomato, onion, avocado and blue cheese on each. Season to taste with salt and pepper.