“Gyoza” are Japanese food wrappers (or dumplings), similar to Chinese “jiaozi.” The dish became popular in Japan following World War II.
 
“YAKI GYO-ZA” was printed in the Honolulu (HI) Star-Bulletin on December 6, 1961. “A Japanese meal of egg foo yong, fried rice and gyoza” was printed in The World (Coos Bay, OR) on January 22, 1963. A recipe for gyoza was printed in the Daily Press (Newport News, VA) on March 2, 1965.
 
Gyoza is sometimes described as similar to ravioli. Gyoza was called “Oriental Raviolis” in a restaurant advertisement in the Los Angeles (CA) Times on December 21, 1968. “The gyoza is described as Japanese ravioli” was printed in The Plain Dealer (Cleveland, OH) on May 4, 1979. “For lunch try gyoza, meat-filled Japanese ravioli, fried crisp, with a spicy dip” was printed in the Texas Monthly in March 1981. 
   
     
Wikipedia: Jiaozi
The Japanese word gyōza (ギョーザ, ギョウザ) was derived from the reading of 餃子 in the Jilu Mandarin (giǎoze) and is written using the same Chinese characters. The selection of characters indicates that the word is of non-Japanese origin. Following the Second World War, Japanese soldiers who returned from northeastern China brought home gyōza recipes.
 
The prevalent differences between Japanese-style gyōza and Chinese-style jiaozi are the rich garlic flavor, which is less noticeable in the Chinese version, and that gyōza wrappers appear to be consistently thinner, due to the fact that most Japanese restaurants use machine-made wrappers. In contrast, the rustic cuisine of poor Chinese immigrants shaped westerners’ views that Chinese restaurant jiaozi use thicker handmade wrappers. As jiaozi vary greatly across regions within China, these differences are not clear. For example, visitors will easily find thin skinned ones at restaurants in Shanghai, and from street food vendors in the Hangzhou region. Gyōza are identical to jiaozi made in Chinese households using store bought machine made wrappers. Gyōza are usually served with soy-based tare sauce seasoned with rice vinegar and/or chili oil (rāyu in Japanese, làyóu (辣油) in Mandarin Chinese). The most common recipe is a mixture of minced pork, cabbage, Asian chives, and sesame oil, and/or garlic, and/or ginger, which is then wrapped into thinly rolled dough skins. Gyoza share similarities with both pierogi and spring rolls and are cooked in the same fashion as pierogi, either boiled or fried.
 
(Oxford English Dictionary)
gyoza, n.
Etymology: < Japanese gyōza (1955 or earlier), probably < Chinese regional (Shandong)

giaozi (Mandarin Chinese jiǎozi : see jiaozi n.).
In Japanese cookery: a crescent-shaped dumpling of thin pastry dough, stuffed with a finely minced paste (typically made of pork, cabbage, and garlic chives), and steam-fried, deep-fried, grilled, or boiled. Also gyoza dumpling. Cf. jiaozi n., potsticker n.
1965   Valley Independent (Monessen, Pa.) 24 June 14/4   Some of the people walking past on their way to work were munching on a kind of meat dumpling called ‘gyoza’.
 
6 December 1961, Honolulu (HI) Star-Bulletin, pg. 5, col. 1 ad:
WATCH KONA TV
EVERY SUNDAY 11:30 A.M.
MRS. M. FUNAKOSHI Demonstrating
“YAKI GYO-ZA”
FREE RECIPES AVAILABLE MONDAY MORNING
(Chun Hoon supermarkets.—ed.)
 
22 January 1963, The World (Coos Bay, OR), “Home Extension News,” pg. 7, col. 2:
Mrs. Dan Sizemore hosted the meeting of the Olive Barber HEU recently for which Mrs. Dale Yunkherr and Mrs. Richard McCutcheon prepared a Japanese meal of egg foo yong, fried rice and gyoza.
 
2 March 1965, Daily Press (Newport News, VA), “Oriental Cooking—In Virginia” by Harriet Nachman, pg. 6, col. 3:
Fort Eustis husbands coming home to a dinner of sushi and gyoza can thank Mrs. Everett Rackley and Mrs. Carl Glenn for the exotic additions to their diets.
(...) (Col. 5—ed.)
“Gyoza, which looks like Italian ravioli minus the tomato sauce, is especially popular with the Chinese as a New Year’s dish and at all times in Japan,” said Mrs. Rackley.
(...)
GYOZA
3 cups flour
1/4 cup water
1/4 lb. ground pork
1/4 lb. ground beef
1/2 hard lettuce of Chinese cabbage
3 green onions (medium size)
3 dry mushrooms (medium size) or small can of mushrooms (2 1/2 oz.)
1 clove garlic
2 teaspoons salad oil
SAUCE
2 tablespoons Shoyu sauce
2 tablespoons vinegar
Dash of Aji-no-moto or accent
Boil water. When wrapping meat around dough, pinch edges lightly so balls will not break open during cooking. Drop balls into water one at a time. Do not over boil. Makes 40 gyoza—10 per person.
   
24 June 1965, Coldwater (MI) Daily Reporter, “Inside Look At Present-Day Red China” by Kenji Nakano (UPI), pg. 7, col. 4:
Some of the people walking past on their way to work were munching on a kind of meat dumpling called “gyoza.”
   
28 March 1968, Fort Worth (TX) Star-Telegram, “Japanese Dinner Note” by Jo Ann Vachule, pg. 3-B, cols. 1-2:
GYOZA
2 dozen sheets of wantan skin
1/2 pound minced pork
1/2 teaspoon salt
1 teaspoon each sugar and cornstarch
2 teaspoons butter
1/2 teaspoon monosodium glutamate
4 green onions, minced
1/3 teaspoon ginger root, ground fine.
 
Cook pork well. Add all other ingredients and cook until onions are tender. Place cooked ingredients on top of wantan skin. Moisten corners and make triangle by bringing opposite sides of skin together.
 
Add about 2 teaspoons oil to large frying pan. Add the filled pastries in one layer and brown on both sides. Add 2 teaspoons of water, cover and steam about 5 minutes.
 
Serve with sauce made of equal quantities of soy sauce and sesame oil to which a pinch of shichimi karashi (Japanese hot pepper) has been added.
 
(Wantan skin is a thin pastry, available at import stores as are other Japanese ingredients.)
   
21 December 1968, Los Angeles (CA) Times, pt. 2-F, pg. 10, col. 4 ad:
NOW GYOZA
(Oriental Raviolis)
A Quick Snack
For Late Shoppers
MIKADO
Japanese Restaurant
12600 RIVERSIDE DRIVE
   
4 May 1979, The Plain Dealer (Cleveland, OH), “Restaurants,” Friday (Weekend Magazine) sec., pg. 29, col. 1:
The gyoza is described as Japanese ravioli: It’s a noodle skin with a meat filling somewhat similar to Chinese deem sum.
     
Google Books
March 1981, Texas Monthly, pg. 20, col. 2:
For lunch try gyoza, meat-filled Japanese ravioli, fried crisp, with a spicy dip.
(Restaurant Takenoya, 2300 South Georgia, Amarillo.—ed.)
 
26 September 1986, The Plain Dealer (Cleveland, OH), “Let your hibachi rust” by Janet Beighle French, Friday! sec., pg. 37, col. 1:
(Shogun Japanese Steak, 20505 Lorain Road, Fairview Park.—ed.)
One can choose “Yaki-Gyoza” (translated “Japanese ravioli”). ...
 
YouTube
How to Make Yaki Gyoza (Fried Dumpling Recipe) | Cooking with Dog
Cooking with Dog
Published on Jun 20, 2009
These delicious Yaki Gyoza, fried dumplings have a crispy outside and juicy filling!
How to Make Yaki Gyoza
https://cookingwithdog.com/recipe/yak…
 
(25 pieces)
120g Ground Pork (4.23 oz)
100g Cabbage (3.53 oz)
50g Onion (1.76 oz)
50g Nira - Garlic Chives (1.76 oz)
 
- Condiments -
1/2 tbsp Soy Sauce
1/2 tsp Sugar
A pinch of Pepper
1 tbsp Sake
1/2 tbsp Sesame Oil
1 tbsp Potato Starch
1 tsp Grated Garlic
1/2 tsp Grated Ginger
1/2 tbsp Oyster Sauce
or 1 tsp Chinese Soup Base
 
YouTube
How To Make Gyoza (Japanese Potstickers) (Recipe)  餃子の作り方 (レシピ)
Just One Cookbook
Published on Jul 8, 2017
Juicy on the inside, crispy and golden brown on the outside, these Japanese pan-fried dumplings, Gyoza, are popular weeknight meal as well as a great appetizer for your next dinner party.
PRINT RECIPE ▶ http://bit.ly/GyozaRecipe
Prep Time: 30 mins
Cook Time: 30 mins
Total Time: 60 mins (inc. marinating time)
Serves: 52 pieces
 
Ingredients:
1 pkg gyoza wrappers (1 pkg = 52 sheets) (See Notes for homemade recipe)
1 Tbsp neutral flavor oil (vegetable, canola, etc) (for frying each batch of gyoza)
¼ cup water (for frying each batch of gyoza)
1 tsp sesame oil (for frying each batch of gyoza)
 
Filling:
¾ lb ground pork (¾ lb = 340 g)
2-3 leaves cabbage (2-3 leaves = 140 g or 5 oz)
2 green onion/scallion (2 green onion = 15 g or 0.5 oz)
2 shiitake mushrooms
1 clove garlic (minced)
1 inch ginger (1” = 2.5 cm) (fresh, grated)
 
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(...)
Gyoza are commonly known as pot stickers.
Commonly known as pot stickers, gyoza are dumplings filled with ground meat, vegetables and other fillings like ginger, garlic and soy sauce.