The phrase "dish in the freezer" refers to a meal or food item that has been stored in the freezer to keep it frozen and preserved until it is ready to be eaten. Full definition
Place dish in the freezer for over an hour or so. (theeverygirl.com)
Place dish in freezer for 15 minutes so fudge sauce can set. (eatpicks.com)
Let cool at room temperature for about 10 minutes, and then place dish in the freezer until ice crystals form around the edges, about 1 hour. (healthyfoodforliving.com)