When the series about the fictional Reagan family, an Irish-American Catholic family in New York City with deep roots in law enforcement, was created, executive producer Leonard Goldberg came up with the idea that there would be a family dinner in every episode—and tonight is no exception. In honor of St. Patrick’s Day, corned beef and cabbage are on the menu, and so is a lively conversation among the clan: Tom Selleck as Frank Reagan, Donnie Wahlberg as Danny Reagan, Will Estes as Jamie Reagan, Vanessa Ray as Eddie Janko, Bridget Moynahan as Erin Reagan, Andrew Terraciano as Sean Reagan, and Len Cariou as Henry Reagan. In this video preview, Selleck, Wahlberg and the Blue Bloods cast fondly recall the origin and importance of the family dinner and why they believe it still resonates with fans. “Family dinners are a great chance to have a reunion of friends as well as a reunion of actors,” Selleck said. Then added, “Audiences don’t like repetition but they like rituals.” And family dinner is definitely a ritual. Tonight, the family will be introducing its newest member Eddie, who is married to Jamie, to their St. Patrick’s Day tradition. “This family dinner is a little less about the food and a little more about the whiskey,” said Wahlberg. And Estes explained, “A Reagan family tradition is the Shamrock in the glass. It’s toast, sip and then throw the Shamrock, and then finish the glass.” “I should weigh 450,000 pounds by now, but somehow I am hanging in there after 250 dinners,” added Wahlberg. “I am known as the eater, but I am still very svelte.” Also, on tonight’s “Guilt” episode, Frank, Baker (Abigail Hawk), Garrett (Gregory Jbara) and Gormley (Robert Clohessy) experience feelings of guilt when Detective Angela Reddick (Ilfenish Hadera), an officer they briefly worked with at 1PP, is shot after Frank reassigned her for not meshing with their team. And Eddie, Danny and Baez (Marisa Ramierz) investigate a man’s murder after Eddie and her partner respond to an altercation between the victim and a neighbor, while Anthony (Steven Schirripa) finds himself at a crossroads when he’s offered a promotion that strains his relationship with Erin. On a final note, Wahlberg said, “To be here for 250 episodes, it’s really beyond. It’s never too late to join the family.” Blue Blood airs Friday nights at 10 p.m. ET/PT on CBS. Next, The Reagans Return for a 12th Season of Blue Bloods and Here Are All the Details!