In a medium bowl, combine the cooked shrimp with lemon juice, olive oil, ½ teaspoon of granulated garlic, and ⅓ teaspoon of cumin. Toss to coat evenly and let sit for 10 minutes.

Heat a non-stick skillet over medium heat, then add the marinated shrimp. Sauté for about 5 minutes until the shrimp turn pink and opaque. Transfer to a cooling plate.

In a separate bowl, whisk together sour cream, mayonnaise, Worcestershire sauce, brown sugar, mustard powder, salt, pepper, and remaining granulated garlic and cumin until smooth.

In a large mixing bowl, combine cooled macaroni, sautéed shrimp, chopped shallot, diced celery, and parsley. Pour the dressing over and fold together until well-coated.

Cover with plastic wrap and refrigerate for at least 30 minutes before serving for the flavors to meld.