Sam McMurray plays an aggressive cancer surgeon just like his role as Dr. Kennedy in The Sopranos (1999).
The poster of a samurai on Jesse's living room wall reads "Courage" in Japanese.
Sam McMurray (Dr. Victor Bravenec) guest starred in episode 2.16, Traffic Ticket (2001), of Bryan Cranston's (Walter White) old show, Malcolm in the Middle (2000). He played a police officer looking to strike a deal with Cranston's on show wife.
"Frings" were a combination of french fries and onion rings sold by burger chain Harvey's in Canada and by unrelated chain Jack in the Box in the US, so it's a good character name for fast food restaurant owner 'Gus' Fring.