Sushi rice seasoning mixture per Chef Ming Tsai
4 cups uncooked sushi rice, cooked per directions on package
1 cup rice vinegar, unseasoned
1/4 cup mirin
1/2 cup sugar
Mix in a small saucepan and heat over medium high just until you start to get small bubbles and sugar is totally dissolved. Add to cooked rice while still hot, turning the rice and fanning until it has cooled somewhat. You have added enough liquid when the rice is glistening but not mushy and has a sweet/tart taste. Wipe down rim of bowl so no rice remains stuck to it and cover with a damp cloth. Allow rice to cool to room temperature, at least 30 minutes.
Here's a very good video on how to roll.
https://www.foodandwine.com/video/ming-tsai-how-roll-sushi If you have more filling than he had, you simply add more rice to cover 2/3 to 3/4 of the nori. A lot of sushi places wrap their mats in plastic wrap to keep them from getting rice stuck in them. I personally don't unless I'm making an inside out roll, but I do clean my mat as soon as I'm done rolling. I let the rice dry in one once, won't do that ever again.
Ming kind of glosses over the cutting part. You cut the roll in half, then in thirds or fourths dependng on the size of your nori and the size you want your sushi piece to be. A piece of sushi is supposed to be one-mouthful only.
One of our favorites is a spicy tuna roll, which I use kimchi base for as that is what Craig likes, but you could use sriracha. You would use this in place of wasabi, just put a small stripe (or large if you have heat loving people) down the middle of the rice along the length. You want to try to get a piece of tuna loin to cut your strips of tuna, but regardless, as mentioned earlier, buy sushi grade fish of any kind. I usually put some green onion strips and maybe some cucumber in it. You could also do avocado.
Another is a shrimp tempura roll, though I usually use panko crumbs as a crust instead of tempura batter. I shell,clean and tail the shrimp and place 2 or 3 on a short skewer so they won't curl, flour, egg wash, and panko, then pan fry. Cool and slice the shrimp in half lengthwise. I place a stripe of wasabi down the length of the roll, green onion, avocado and cucumber, and the shrimp of course. You can also use Japanese mayo for this, which can be purchased at an oriental market or made up at home.
Crab rolls can be made the same as the shrimp tempura or just use already cooked crab.
To make vege rolls, I cook spinach until just wilted with just a few drops of water, salt and pepper. When done, I add a few drops of sesame oil, which you can do or not do. Cool spinach to room temperature. I also use sliced cucumber, green onion, and grated carrot, avocado if I have it. Again, you can use wasabi or Japanese mayo.
Occasionally, I will make stuffed squid sushi. You use small squid bodies and the tentacles and flappers. If they are not cleaned, you will need to remove the head and tentacle, discard the head parts, and pop the beak out of the tentacles, reserving the tentacles. Clean the guts out of the body and make sure to remove the quill inside. Cut the flappers off and reserve. Cook the bodies in boiling salted water for 45-60 seconds depending on size (you'll want a body that is 3 inches or less for this), remove and place in ice water to cool and then drain. Add a bit of mirin, soy sauce and sugar to the water, then cook the tentacles and flappers but only cook for about 30-45 seconds. Chop up the tentacles, flappers, and some cucumber, add some toasted sesame seeds, mix with some cooked sushi rice and stuff the squid bodies. You want them to be firm, but you don't want them bursting open either. Slice into 3 or 4 pieces each depending on size.
You can also make hand rolls. Cut a piece of nori diagonally into 2 equal triangles, roll into a cone shape, run some of the vinegar water/glue onto the outside edge to glue it into place, fill with rice and whatever toppings you wish.
The just rice and topping sushi can be made by forming rice into a rounded rectangular shape using the palm of one hand and fingers of other. You want it to be fairly compact but not totally squished. You will need some wasabi or mayo on top that will act as a glue for whatever piece of fish you put on it The piece of fish should cover but not overlap the top of the rice. You can also butterfly a shrimp and lay it over the top. Tail on or off depending on what you want for your presentation/ease of eating.
If you have people that don't like spicy at all, just leave the wasabi out of the rolls and provide some separately for those that do. Also, provide some even if you do use it in the rolls as some people like even more. You will also want to provide some pickled ginger, which can be purchased or made at home.
Hopefully you have an oriental market handy as the things you will need like rice, nori, rice vinegar, mirin, wasabi, etc are generally much less expensive than in a regular grocery store.
Oh, do all your prep work first and preferably ahead as it usually takes some time to cut those thin strips of cucumber and green onions, cook any seafood needed, etc. And, of course, the rice has to have time to cook and cool. You will want to peel your cucumber, slice in half lengthwise and remove the seeds, then slice. Grate your carrots. Cover things with plastic wrap as you are done with them and refrigerate. You DO NOT use hot or even warm rice for sushi.
Craig's brother made sushi for a 4th of July party once. He put blue food coloring in the rice water and then used strips of roasted/peeled red bell pepper and strips of cooked chicken. I'm sure he seasoned the chicken with some kind of Asian seasonings but don't remember. He said it was a real novelty and that people also really liked them.