Make the sushi rice : Place rice in fine-mesh colander and rinse well to remove excess starch; drain. Transfer to a 2 1/2- to 3-quart heavy saucepan. Add water. Cover with tight fitting lid and bring to boil. Reduce heat to low or medium-low. Very gently simmer, covered, about 20 minutes or until water is absorbed. Remove from heat. Let stand, covered, for 15 minutes. Transfer rice to a large baking dish or large bowl. Slightly cool. Sprinkle with rice vinegar; very gently toss until combined. Cool to room temperature. Cover with damp towel to prevent rice from drying out. When making sushi, you want the rice to be close to room temperature (hot, steaming rice will make the seaweed soggy).
Meanwhile, for the spinach-egg filling, squeeze as much water out of the spinach as possible.
Finely chop the spinach. Gently fry the eggs with the spinach and season with salt. Let cool before rolling sushi.
To roll the sushi, have all your ingredients ready.
Lay out the sushi mat, with the bamboo running horizontally. The sushi mat should be completely wrapped in plastic wrap (otherwise the rice will stick to it). Lay the nori on the mat.
Wet your hands, fling off excess water and grab about 3/4 cup of the sushi rice. Damp hands will prevent the rice from sticking. Use your fingertips and gently spread out the rice all over the seaweed.
You don't want too much rice - just enough to barely cover.
Lay down the ham.
Spoon about 3 tablespoons of the egg/spinach mixture. Move the nori so it is flush with the bottom of the mat.
Now bring up the edge of the mat.
Begin rolling - but keep the edge of the bamboo mat up on top of the rice. Roll with one hand, and use the other hand to gently tug the mat. This will ensure a tight roll.
See how I keep the edge of the bamboo mat up? Continue rolling and gently tugging until roll is complete.
Give it nice final tug back to tighten roll.
There you go. See how even the roll is?
Dip the tip your knife in water, and slice into 6 even pieces. A wet knife tip will prevent sticking.