How do I make an authentic sushi?

Mango, avocado, and nearly all sushi rolls are not "authentic" in the sense you are using the word — they are not the way a traditional sushi chef would do things in Japan. Most traditional rolls would be very simple, and small, with one or two ingredients other than the rice and the nori wrapper. Avocados and mangos are not indigenous to Japan, so before there was a lot of world trade, they were not found in sushi there. Can you spot why this roll is not authentic? Good.Anyway, the quest for authenticity is misplaced. Sushi is meant to be enjoyed, made out of local, fresh fish ingredients. To my mind, the best sushi places in Japan are either very humble little shops near the ocean where they specialize in sashimi and simple nigiri (fish on top of rice, no rolls, no seaweed) from locally-caught fish. Unless you count miso soup and tea, there's not much of a menu beyond the sushi — no appetizers, deserts, cooked food. And second, there are some more cheerful, fun places in shopping malls or busy streets that are a little like the sushi restaurants in America, but they have a few different formats and conventions.If you are in a place outside of Japan with a particular kind of delicious fish, or vegetable, or fruit, it is more in the spirit of sushi to go with that than to try to recreate Japanese styles with ingredients that are probably scarce, or expensive, or not as good as they would be in Japan. If you're in mango country, then by all means, use a mango.There is also a style called American sushi, that's the kind with the avocados, macadamia nuts, deep fried things, inside out rolls, spicy rolls, and all all too much mayonnaise, mostly concentrating on rolls. It's well enough established that there are universal names and ways of making the American rolls. Even in Japan, they call it American sushi and they do it the American way. Here is some American-style sushi, nothing wrong with that.If you really want to learn sushi as a home chef, I would first concentrate on the basics before worrying too much about ingredients. First learn how to make the rice, how to do the rolls. Then learn good knife skills on slicing fish. Then go to a good Japanese supermarket and get some nice sushi-grade fish ingredients, sometimes you can get them pre-sliced. In most towns you can take classes on how to make sushi, or hire a personal sushi instructor, you can even host a sushi class party.

I consider traditional as what was in Japan before sushi became popular in the US.  It included nigirizushi and a very limited number of maki. I was a kid but I do remember kappamaki(cucumber), kampyomaki(dried gourd simmered in various umami components), oshinkomaki(mostly filled with takuan) or futomaki( thick wrap filled with savory ingredients from the sea, tamago and vegetables. NO fruit or mayo!) All of the recipes for these can be found on the internet. Most of these maki cannot be found in most American sushi bars. The sushi shops would deliver on bicycles while balancing big round trays on their shoulder. One hand balancing the wares, One hand on the handlebar. Riding up and down hills!

There are so many types of sushi, it is hard to answer that question. Sushi just means "vinegared rice." It is the foundation of all types of sushi. But if you just want to do rolls, there are kits. To make vinegared rice, there are packets to add to hot rice, or you can look up the recipe. I've had them both, and while "genuine" is better, klutzes such as myself use the packets.

As one of the other posters said, learn how to make sushi rice, there are many good recipes for that on the internet. The basis is a sushi rice, a rice cooker and the sushi vinegar, make sure you follow all the instructions and you will have your base. Now, if you want to make maki rolls, you will need Nouri (seaweed) and a sushi mat, and you can fill it with anything (I often use, avocado, cream cheese, cucumber, smoked salmon). Next, if you want to make Nigiri Sushi you will need to get some sashimi grade fish. There is one primary web site I use that sends frozen fish to your door, fishforsushi. According to my research its better to get it frozen and defrost it properly, rather than buy something fresh. Finally if you want to go sashimi, just skip the rice lol. Actually a sashimi salad is fantastic, just add fish to a spring salad and make a wasabi / ginger dressing (google that recipe).

http://cookpad.com/recipe/193578