The dinner at the farmhouse takes place on Thursday. The day of RJ's specials being served on the menu at the restaurant is Friday. But in the course of the movie, there is at least one day in-between the farmhouse dinner and the night of RJ's specials on the menu.
Anna could not find all of the unusual ingredients for the sauce by first shopping on Christmas Day morning.
A doctor flirting with a patient's relative is unethical.