Sushi doesn't have to be complicated. The ingredients are up to you and easy to get.
Sushi rice isn't complicated either. You do need short grain rice. You also need some rice wine vinegar, salt, and sugar. Any package of sushi rice will have directions on how to cook it. If you look online for advice, you will find hundreds of variations on the theme. Basically, you cook the rice and cool it. Once cooled, you season it with the vinegar, salt, and sugar mixture. Now it's ready to use for makinori - pieces of raw fish atop a clump of rice - or norimaki - rice, veggies, and sometimes fish wrapped in sheets of nori. Nori wraps you can get at any grocery store. Nori is simply seaweed, one of bajillions, which is dried and made into sheets.
We bought the sushi-grade tuna from Seattle Fish Company on California Ave. in our 'hood. Hey, they also have smoked salmon collars. If you've not tried these and you like salmon, you are missing the richest part of the fish. I'll post about them in the near future. I sliced the tuna relatively thin and added avacado and cucumber to make norimaki.
You can see the tuna rolls here in front of S. You can also see that it's just too tempting to have a big hunk of sushi-grade tuna in the kitchen and NOT think you're going to get to enjoy it without the trappings. This is known as sashimi - just the raw fish, often dipped in wasabi. S has a mixture of a soy mushroom sauce and wasabi in that little dish. If you're going to treat yourself to this, just eat it any which way you like it, that's what we say.
I also threw some shrimp in a pot of boiling water for about a minute and made some shrimp rolls. Same process. Some of these rolls had red pepper, strips of jalapeno, cucumber and zucchini.
This is not that hard to do. You can make a party out of it. Let everyone roll their own, so to speak. And it's about 100 times cheaper than having sushi in a sushi joint.