Preheat oven to 400F.
Mix the shrimp, olive oil, lemon juice, garlic, onion powder, salt and pepper together.
Place shrimp on baking tray and roast for 10 minutes.
To make the salad dressing, blend the mayo, mustard, lemon juice, garlic powder, salt and pepper together.
Toss the dressing with the chopped lettuce, chopped cucumber, and roasted shrimp.
Garnish with the chopped parsley and sliced almonds.