The “Italian hot dog” was invented at Jimmy Buff’s restaurant at 14th Avenue and 9th Street, Newark, New Jersey, that was opened in 1932 by James “Buff” Racioppi. The dish was first served to friends, and then made a regular part of the menu.
 
Jimmy Buff’s website states that an Italian hot dog is:
 
“A Jimmy Buff Italian hot dog goes on a quarter of a large roll of Italian ‘Pizza’ bread (sort of a fat pita). The dog is cooked in Hot Oils and then topped with sauteed onions, peppers and potatoes.”
   
   
Wikipedia: Italian hot dog
An Italian hot dog is a type of hot dog popular in New Jersey, United States.
 
Preparation
There are numerous ways to prepare an Italian hot dog. The basic dish consists of a cooked (usually deep-fried) hot dog placed in an Italian roll or pizza bread, and topped with a combination of fried bell peppers, onions, and potatoes. The Italian Hot Dog is a New Jersey tradition similar to Philadelphia’s cheesesteak or other regional sandwiches.
 
History
James “Buff” Racioppi, founder of Jimmy Buff’s in Newark, New Jersey, invented the Italian hot dog in 1932.
       
Jimmy Buff’s
A Little History
Jimmy Buff’s of 14th Ave. & 9th St. in Newark, NJ is where the hotdog with an Italian twist was first concocted by the founder James “Bluff” Racioppi in 1932. Grandpa got his nickname from his style at the card table. Translation from Italian to English came up with the nickname “BUFF”. In the 20s and 30s everyone had a nickname and hence James Racioppi became known as “Jimmy Buff”.
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What’s an Italian Hotdog?
A Jimmy Buff Italian hot dog goes on a quarter of a large roll of Italian “Pizza” bread (sort of a fat pita). The dog is cooked in Hot Oils and then topped with sauteed onions, peppers and potatoes.
 
You can also order a double, which is two dogs on a half a “Pizza” roll.
 
7 March 1968, The Star-Ledger (Newark, NJ), “Personally Speaking” by Jerry Nussbaum, pg. 25, col. 3:
On or about March 18, when another link in the Jimmy Buff’s “Hot Style Italian Hot Dogs” opens at 1019 South Orange Ave., folks can have ample samples. Top man of Jimmy Buff’s is Thomas Racioppi, a fine example for the tid-bit. He’s 5-ft. 10 and weighs 240 lbs. The restaurants were established by his late dad. There are now eight.
 
27 January 1971, The Rockland County Journal-News (Nyack, NY), “Lost Carrots Create a Sur-prize Ending” by Helen Giordano, pg. 10, col. 5:
Just remembered, that pepper belonged to a fry pan of Italian hot dogs, franks cooked with onions, potatoes and peppers in hot oil.
 
8 July 1981, The Courier-News (Bridgewater, NJ), “Italian hot dogs by the inventor” by Ken Quaas, pg. C1:
The eatery is a 13-month-old branch of the original Jimmy Buff’s of Newark, where the hot dog with an Italian twist was first concocted in 1932 by the founder of the dining spot, James “Buff” Racioppi.
 
Buff’s Italian hot dog is a blend of frankfurter, potatoes, onions and peppers, all fried in soybean oil and tucked neatly into a roll.
 
The sandwich was first served as a treat by Racioppi to his close friends who visited the restaurant, according to his daughter-in-law, Lucille, who supervises the busy noontime shift at the North Plainfield establishment.
   
Google Books
Hot Dog:
A Global History
By Bruce Kraig
London, UK: Reaktion Books
2009
Pg. 90:
In and around this state (New Jersey—ed.), with its large Italian population, there are ‘Italian hot dogs’, deep fried and served on crusty rolls, with fried or stewed potatoes, and cooked onions and green pepper strips. The last of these, bell or hot peppers, either cooked or pickled, are characteristic of the southern Italian-Sicilian contribution to regional fast food.
 
30 May 2010, San Francisco (CA) Chronicle, “The Best Hot Dogs in America” by Jane and Michael Stern, Parade magazine, pg. 8, cols. 2-3:
Italian Hot Dog:
Northern New Jersey
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In wiener joints around Newark, a half-round of sturdy bakery bread is squeezed open to become a pocket that resembles a pita on steroids, then stuffed with a pair of deep-fried dogs, a heap of sauteed onions and peppers, and a handful of crisp-fried potato chunks: Behold, the Italian hot dog!
 
25 September 2013, New York (NY) Times, “Dog Ziggety: New Jersey’s Own” by Robert Sietsema, pg. D7, col. 2:
THE ITALIAN HOT DOG One to three deep-fried slender beef franks stuffed inside a hallowed-out loaf of pizza bread with fried potatoes, peppers and onions.