Finely dice the celery into 1/4-inch pieces, mince the red onion, and zest the lemon, setting each aside in separate bowls. Chop the fresh chives and measure out the mayonnaise and Greek yogurt. This advance prep ensures you're ready to move quickly once the pasta is cooked, preventing the salad from becoming warm or mushy while you're still chopping.

Bring a large pot of salted water to a rolling boil, then add the cavatappi pasta. Cook for 1-2 minutes past al dente—this slightly softer texture works better for a cold pasta salad as it absorbs the creamy dressing more readily. Stir occasionally to prevent sticking.

Drain the pasta in a colander, then rinse thoroughly with cold water while tossing gently to remove starch and stop the cooking process. This ensures the pasta remains tender but not mushy and prevents it from sticking together. Transfer the cooled pasta to a large mixing bowl.

In a small bowl, whisk together the mayonnaise and Greek yogurt until smooth and combined. Add the lemon juice, lemon zest, celery salt, salt, and black pepper, stirring to combine. The Greek yogurt lightens the richness of the mayo while adding tang—I find this balance keeps the salad from feeling heavy. Taste and adjust seasonings as needed.

Cut the cooked lobster into 1-inch chunks and add them to the cooled pasta. Pour the creamy dressing over the pasta and lobster, then add the prepared celery, red onion, and chives. Fold gently but thoroughly to distribute the ingredients evenly, taking care not to break apart the delicate lobster meat. I recommend folding gently with a rubber spatula rather than stirring vigorously to keep the lobster chunks intact.

Transfer the lobster pasta salad to a serving dish or individual bowls and refrigerate for at least 30 minutes before serving to allow the flavors to meld and the salad to reach an ideal cold temperature. The cold temperature also helps the dressing cling better to the pasta.