In a small bowl, whisk together lemon juice, olive oil, mustard, oregano, salt and black pepper. Set aside.
Place bulgur in a large bowl. Stir in 2 cups boiling water. Cover with plastic and allow to stand for 5 minutes. Stir in tomatoes, cucumber, parsley, mint and 2 tablespoons of lemon dressing. Cover and refrigerate 1 hour.
Toss the shrimp with 1 tablespoon of dressing and set aside.
In a large bowl, toss together lettuce, onion, olives and remaining dressing. Equally divide among 4 dinner plates. Top each serving with bulgur, shrimp and feta.