Given the task definition and input, reply with output. In this task, you will be presented with the directions of a recipe separated by "," and have to fill in the "___" which is a step that is missing from the recipe.

Prepare macaroni according to package directions; rinse with cold running water, Stir together celery, green onions, mayonnaise, parsley, Dijon mustard, tarragon, vinegar, sugar, salt, and pepper,______, Cover and chill 1 hour,
Coarsely chop Perfect Poached Shrimp; stir shrimp and mayonnaise mixture into pasta