Chinese version
Chinese dumplings (jiaozi) may be divided into various types depending on how they are cooked:
  • Boiled dumplings; (shuijiao) literally "water dumplings" (水餃; pinyin: shuǐjiǎo).
  • Steamed dumplings; (zhengjiao) literally "steam-dumpling" (蒸餃; pinyin: zhēngjiǎo).
  • Shallow fried dumplings (guotie) lit. "pan stick", known as "potstickers" in N. America, (鍋貼; pinyin: guōtiē), also referred to as "dry-fried dumplings" (煎餃; pinyin: jiānjiǎo).
Dumplings that use egg rather than dough to wrap the filling are called "egg dumplings" or (蛋餃; pinyin: dànjiǎo).
Common dumpling meat fillings include pork, mutton, beef, chicken, fish, and shrimp which are usually mixed with chopped vegetables. Popular vegetable fillings include cabbage, scallion (spring onions), leek, and Garlic chives. Dumplings are eaten with a soy sauce-based dipping sauce that may include vinegar, garlic, ginger, rice wine, hot sauce, and sesame oil.

Dumplings Jiǎozi are one of the major foods eaten during the Chinese New Year, and year round in the northern provinces. They look like the golden ingots yuan bao used during the Ming Dynasty for money and the name sounds like the word for the earliest paper money, so serving them brings the promise of wealth, good luck and prosperity. Many families eat these at midnight on Chinese New Year's Eve so they have money at the changing of the years. Some cooks will even hide a clean coin in one for the most lucky to find.
Jiǎozi are eaten all year round and can be eaten at any time of the day – breakfast, lunch or dinner. They can constitute one course, starter or side dish, or the main meal. Every family has its own preferred method of making them, with favourite fillings, and of course, jiǎozi types and preparation vary widely according to region.

Cantonese style Chinese dumplings (gaau) are standard fare in dim sum. Gaau is simply the Cantonese pronunciation for 餃 (pinyin: jiǎo). The immediate noted difference to jiǎozi is that they are smaller and wrapped in a thinner translucent skin, and usually steamed. In other words, these are steamed dumplings. The smaller size and the thinner pastry make the dumplings easier to cook through with steaming. Fillings include shrimp, scallop, chicken, tofu, mixed vegetables, and others. The most common type is shrimp dumplings (har gow). In contrast to jiǎozi, gaau are rarely home-made. Similar to jiǎozi, many types of fillings exist, and dim sum restaurants often feature their own house specials or innovations. Dim sum chefs and artists often use ingredients in new or creative ways, or draw inspiration from other Chinese culinary traditions, such as Chiuchow, Hakka, or Shanghai. More daring chefs may even incorporate a fusion from other cultures, such as Japanese (teriyaki) or Southeast Asian (satay, curry), while upscale restaurants may use expensive or exotic ingredients such as lobster, shark fin and bird's nest. Another Cantonese dumpling is the jau gok.

Jiǎozi were so named because they were horn shaped. The Chinese for "horn" is jiǎo (角), and jiǎozi was originally written with the Chinese character for "horn", but later it was replaced by a specific character 餃, which has the food radical on the left and the phonetic component jiāo (交) on the right.

According to folk tales, jiǎozi were invented by Zhang Zhongjing, one of the greatest practitioners of traditional Chinese medicine in history. They were originally called "娇耳"(Pinyin: jiao'er) because they were used to treat frostbitten ears.

Japanese version
The Japanese word Gyōza (ギョーザ, ギョウザ) was derived from the reading of 餃子 (Jiǎozi in Mandarin Chinese) in the Shandong Chinese dialect (giaozi) and is written using the same Chinese characters.

The most prominent differences of Japanese-style gyōza from Chinese style jiǎozi are the rich garlic flavour, which is less noticeable in the Japanese version, and the fact that Japanese gyōza are very lightly flavoured with salt, soy, and that the gyōza wrappers are much thinner. They are usually served with soy-based tare sauce seasoned with rice vinegar and/or Rāyu (known as chilli oil in English, làyóu (辣油) in China). The most common recipe found is a mixture of minced pork, cabbage, and Nira (Chinese chives), and sesame oil, and/or garlic, and/or ginger, which is then wrapped into thinly-rolled dough skins. In essence, gyōza is a cross between a pierogi and an egg roll.
Gyōza can be found in supermarkets and restaurants throughout Japan. Pan-fried Gyōza is sold as a side dish in almost all ramen and Chinese restaurants.

The most popular preparation method is the pan-fried style called Yaki-gyōza (焼き餃子), in which the dumpling is first fried on one flat side, creating a crispy skin. Then, water is added and the pan sealed with a lid, until the upper part of the gyōza is steamed. Other popular methods include boiled Sui-gyōza (水餃子) and deep fried Age-gyōza (揚げ餃子).

Store bought frozen dumplings are often prepared at home by first placing them in a pot of water which is brought to a boil, and then transferring them to a pan with oil to fry the skin.
Nepali version
Nepali version is known as Momo. Flour is filled, most commonly with ground Water Buffalo meat. Often, ground lamb or chicken meats are used as alternate to water buffalo meat. Finely chopped onion, minced garlic, fresh minced ginger, turmeric, cumin powder, coriander/cilantro, etc are added to meat for flavouring. Sauce made from cooked tomatoes flavoured with timur (Szechwan pepper), minced red chillies is often served along with momo.

Guotie (simplified Chinese: 锅贴; traditional Chinese: 鍋貼; pinyin: guōtiē; literally "pot stick") is pan-fried jiǎozi, also known as potstickers in North America, or yaki-gyoza in Japan. They are a Northern Chinese style dumpling popular as a street food, appetizer, or side order in Chinese. This dish is sometimes served on a dim sum menu, but may be offered independently. The filling for this dish usually contains pork (sometimes chicken, or beef in Muslim areas), cabbage (or Chinese cabbage and sometimes spinach), scallions (spring or green onions), ginger, Chinese rice wine or cooking wine, and sesame seed oil.
Guotie are shallow-fried in a wok (Mandarin 'guo'). A small quantity of water is added and the wok is covered. While the base of the dumplings is fried, the upper part is steamed and this gives a texture contrast typical of Chinese cuisine.

An alternative method is to steam in a wok and then fry to crispness on one side in a shallow frying pan.
Exactly the same dumpling is boiled in plenty of water to make jiǎozi and both are eaten with a dipping sauce.
Three or five folds are made on one side of the round wrapper that is rolled so that the edges are thinner than the middle. This gives the base a large surface area that helps to give the dumpling stability to stand up in the pan.
The Chinese method of preparing the dough is to pour boiling water onto the flour and letting stand for five minutes and then adding a small quantity of cold water. This helps to activate the gluten in the dough.

Other names for guotie:
Wor tip (Cantonese Jyutping: wo1 tip3) is the Cantonese name for guotie'

The first mention in literature dates back to the Song Dynasty (960-1280 A.D.) in ancient China reporting the guotie as being exceptionally good for the human soul.

Ref: Wiki Jiaozi