Mother’s Restaurant, at 401 Poydras Street in New Orleans, opened in 1938. The “Debris” sandwich is defined on the restaurant’s website as “The roast beef that falls into the au jus gravy in the pan while roasting in the oven. A Mother’s original.”
 
“Debris, the crackling charred ends of roast beef” was printed in New York magazine on January 27, 1975.
       
The Times-Picayune (New Orleans, LA) explained on February 2, 1979:
       
“And then there is the famous ‘DeBris’ sandwich, named in honor of retired Times-Picayune advertising executive Larry DeBuys, who one day asked Simon Landry to make him a po-boy sandwich out of the shredded roast beef remnants which fell into the pan when the meat was being sliced.”
     
“Since your name is DeBuys, we’ll just call the sandwich a “DeBris,’” Mother’s owner Simon Landry said. Laurence R. DeBuys Jr. died at age 81 in 1987.
     
       
Mother’s Restaurant (401 Poydras, New Orleans, LA)
History of Mother’s Restaurant
Mother’s Restaurant opened its doors in 1938 on Poydras Street’s “Restaurant Row”, situated between a thriving waterfront and the courthouse. Owners Simon and Mary (Mother) Landry and his large family cooked up po’ boys for lines of longshoremen and laborers, newspapermen and attorneys.
(...)
DEBRIS
Ever picked the shavings off a freshly carved roast? When a customer asked Simon Landry to add the bits of roast beef that had fallen into the gravy while he was carving it to his sandwich, he replied “you mean some of the debris?” And just like that, another definitive Mother’s term was coined.
(...)
Debris \ˈdā-ˈbrē\ n.
$12.50 reg | $11.50 sm
(The Original) w/ au jus gravy. The roast beef that falls into the au jus gravy in the pan while roasting in the oven. A Mother’s original.
       
Google Books
27 January 1975, New York magazine, “Food” by Mimi Sheraton, pg. 68, cols. 2-3:
I could at least restore my faith in food and humankind by starting the day with breakfast at Mother’s, bolstering myself with hot biscuits, grits gleaming with melted butter, and debris, the crackling charred ends of roast beef.
 
2 February 1979, The Times-Picayune (New Orleans, LA), “Mother’s—‘Hot Pot Coming Through!’” by Stella Pitts, Fanfare sec., pg. 9, col. 2:
And then there is the famous “DeBris” sandwich, named in honor of retired Times-Picayune advertising executive Larry DeBuys, who one day asked Simon Landry to make him a po-boy sandwich out of the shredded roast beef remnants which fell into the pan when the meat was being sliced.
 
“Since your name is DeBuys, we’ll just call the sandwich a “DeBris.’” Mr. Landry said, and today, many customers at Mother’s declare that “DeBris,” dripping with gravy and coated with hot yellow mustard, is the best sandwich in the world.
 
10 June 1984, Philadelphia (PA) Inquirer, “Peppery Fare Spices Up the Experience” by Elaine Tait, pg. P1:
Mother’s, 401 Poydras, had another sandwich I loved. The Roast Beef Poor Boy is made with a whole long loaf of bread with mustard on one cut surface and mayonnaise on the other. The filling is ample and contains slices of warm, freshly sliced roast beef, shredded fresh cabbage, pickle slices and what New Orleans people call debris (pronounced DAY-bree). It consists of little bits and pieces of the roast soaked in the natural meat juices that exude in cooking.
   
12 July 1984, Miami (FL) Herald, “Dining with Natives” by Linda Cicero, pg. 1E:
Mother’s: Natives say this is the best place in town for a po’ boy sandwich. Hams, turkeys and beef roasts are baked right there, carved to order then moistened with drippings (which New Orleaneans call debris, pronounced DAYbree). The generous portions are slapped into a long, thin roll lathered with mayonnaise and mustard and dressed with shredded fresh cabbage and pickles, all for less than $4—and unless you’ve got a gargantuan appetite, these are sandwiches that will easily feed two.
   
27 August 1987, The Times-Picayune (New Orleans, LA), “Deaths,” pg. B-14, col. 4:
Ex-adman L. DeBuys Jr. dies at 81
Laurence R. DeBuys Jr., a 44-year employee of the Times-Picayune’s advertising department, died Wednesday t JoEllen Smith Medical Center after a long illness. He was 81.
 
Mr. DeBuys was born in Houma, La., graduated from Jesuit High School and attended Tulane University. He started work in the newspaper’s advertising department in January 1932 and retired as an advertising representative in April 1976.
 
1 November 1987, The Times-Picayune (New Orleans, LA), “Sandwiches” by Kathleen Pons, Restaurant Guide, pg. 40, col. 2:
Mother’s: (...) The Ferdi Special is ham with debris gravy and cole slaw. You can get a hot roast beef po-boy or a po-boy with just the debris (met which falls into the pan from the roast) gravy.
 
8 November 1989, Dallas (TX) Morning News, “A Taste of America: In New Orleans, Mother’s best includes lots of beef and gravy” by Jane and Michael Stern, pg. 5F:
You eat fast and try to catch falling debris (a local term for shreds of beef that enrich the gravy), and although the bread stays intact, the table over which you have ingested this majestic work of culinary art looks like the aftermath of a world-class food fight.
 
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Mother’s Restaurant
@MothersNOLA
Ever wonder where the terms “Ferdi, Ralph, and debris” come from? Read about the culinary history of Mother’s in this article from The Times-Picayune in 1979. Always a neighborhood hangout, those names refer to regular customers. #localfood #nolaopen
@IanMcNultyNOLA
H/T: Pete dB.
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