Chinese-American actor Victor Sen Yung made the most of his recurring role. In the process, he became a fan favorite and the focus of two episodes: "Mark Of Guilt" (#316) and "The Lonely Man" (#404).
"Victor was just absolutely delightful," series creator David Dortort told the Archive of American Television. "He loved the part; he loved doing it. In fact, he began to develop fans, to the extent that I wrote him in as the feature part in a number of shows."
Sen Yung, born October 18, 1915 in San Francisco, got his first break in the 1938 comedy Charlie Chan in Honolulu as the title character's "number two son," Jimmy Chan. He went on to appear opposite Sidney Toler in Shadows Over Chinatown, The Chinese Ring, Docks of New Orleans, Charlie Chan at the Wax Museum, Charlie Chan in Rio, Dead Men Tell, The Trap, The Golden Eye, Dangerous Money and Castle in the Desert. Sen Young got replaced in the series by Benson Fong's Tommy Chan character.
During World War II, Sen Yung served in the United States Air Force in real life, appearing in the military play and film Winged Victory, and portrayed such Japanese characters as Joe Totsuiko in Humphrey Bogart's Across the Pacific.
Other films of note for the California native include The Good Earth (1937), crime noir thriller Woman on the Run (1950), Ginger Rogers' The Groom Wore Spurs (1951), John Garfield's The Breaking Point (1951), independent sci-fi film She Demons (1958), the musical Flower Drum Song (1961) and Sen Yung's final big-screen appearance, The Man With Bogart's Face (1980).
Arguably his greatest role came as lawyer clerk Ong Chi Seng in Bette Davis' The Letter (1940).
A stint in early '60s TV show Bachelor Father paved the way for the cook role he'd fill on Bonanza.
According to IMDb, Sen Yung was an accomplished Cantonese-style chef and the author of 1974's Great Wok Cookbook.
He also had a regular role in the '70s TV series Kung-Fu plus prior character actor gigs (usually as an Asian stereotype) on Death Valley Days (as episode lead Quon Kee), Perry Mason, Here's Lucy, Mister Ed, Hawaii Five-O and Get Smart.
In 1972, Sen Yung was on Pacific Southwest Airlines Flight 710, which was hijacked. The FBI stormed the plane, and in the ensuing gunfire Sen Yung was shot in the lower back. He and another wounded passenger survived, but a third passenger and the two hijackers were killed.
Sen Yung, who'd been billed at times as Victor Young, passed away in 1980 at his North Hollywood home. What was first investigated as a potential murder was later deemed an accidental natural gas poisoning from a gas leak.
Bonanza's Pernell Roberts funded Sen Yung's funeral and provided the eulogy.
Per Wikipedia, the Victor Sen Yung Memorial Scholarship is awarded each year by the Chinese Alumni Association of the University of California, Berkeley, where Sen Yung majored in animal husbandry.