Peel and devein the shrimp.
Add parsley, garlic, lemon zest, ⅛ teaspoon of salt, and ⅛ teaspoon of pepper to a small bowl and stir. Add shrimp and let marinate for 10 minutes.
Preheat the oven to 400°F. Roast the bell peppers for 15-20 minutes. Once done, move the cooked peppers to a plate. Then put the shrimp on the same baking sheet used and roast for about 3 minutes on each side.
Cut the roasted bell peppers into 1-inch pieces and save for assembly.
In a small bowl, whisk together the remaining salt, pepper, olive oil, mustard, honey, and lemon juice.
In a large salad bowl, combine cucumber, tomatoes, romaine lettuce, bell peppers, avocado, corn, and shrimp. Toss well with the dressing. Serve immediately.