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.

Mix first 3 ingredients, Add enough water to pineapple juice to make 1 cup, Chill mixture until thick,______, Add cream cheese, Mix thoroughly, Add celery, nuts and pineapple, Let stand in the refrigerator 1 hour, then whip in 1/2 pint whipping cream,
Whip until fluffy