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

Heat a non-stick skillet over medium heat, then add the marinated shrimp. Sauté for about 5 minutes until fully cooked and opaque, then transfer to a plate to cool.

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

In a large mixing bowl, combine the cooled macaroni, cooked shrimp, chopped shallot, diced celery, and chopped parsley. Pour the dressing over and stir until coated.

Cover the bowl and refrigerate for at least 30 minutes to meld flavors before serving.