Crafting these avocado rice balls is a surprisingly simple and meditative process. Follow these detailed steps to ensure perfect results every time.

Part 1: Preparing the Perfect Seasoned Rice

1. Rinse the Rice: Place the 2 cups of sushi rice in a fine-mesh sieve. Rinse it under cold running water, gently swishing the grains with your hand. Continue until the water runs clear. This step is crucial; it removes excess surface starch, which prevents the rice from becoming gummy and ensures a clean, distinct grain texture. Drain the rice thoroughly.
2. Cook the Rice: Transfer the rinsed rice to a medium saucepan or a rice cooker. Add the 2 ½ cups of water. If cooking on the stovetop, bring the water to a boil, then immediately reduce the heat to the lowest possible setting, cover with a tight-fitting lid, and let it simmer for 15-20 minutes, or until all the water has been absorbed. Do not lift the lid during this time. Once cooked, remove the pot from the heat and let it stand, still covered, for another 10 minutes. This allows the rice to steam and become perfectly tender.
3. Prepare the Sushi Vinegar: While the rice is cooking, prepare the seasoning. In a small bowl, combine the ¼ cup of rice vinegar, 2 tablespoons of sugar, and 1 teaspoon of salt. Whisk vigorously until the sugar and salt have completely dissolved. You can gently heat this mixture in the microwave for 20-30 seconds to help the solids dissolve faster, then let it cool.
4. Season the Rice: Once the rice has rested, transfer it to a large, non-metallic bowl (a wooden or glass bowl is ideal as metal can react with the vinegar). While the rice is still hot, slowly drizzle the prepared sushi vinegar mixture over it. Use a rice paddle or a spatula to gently “cut” and fold the vinegar into the rice. Use a side-to-side, slicing motion rather than stirring to avoid mashing the grains. Continue until the rice is evenly coated and has a glossy sheen. Let the rice cool down to room temperature, or at least until it’s cool enough to handle. You can speed this up by fanning the rice as you fold.

Part 2: Creating the Creamy Avocado Filling

1. Prepare the Avocado: Cut the 2 ripe avocados in half lengthwise and remove the pits. Scoop the flesh into a medium bowl.
2. Mash and Season: Immediately add the 1 tablespoon of lime juice to the avocado. This is the key to keeping its beautiful green color. Using a fork, mash the avocado to your desired consistency – some prefer it perfectly smooth, while others like a few small chunks for texture.
3. Add Flavor: Stir in the 1 tablespoon of soy sauce and 1 teaspoon of toasted sesame oil. Mix until everything is well combined. Taste the filling and adjust the seasoning if necessary. You might want a little more soy sauce for saltiness or a dash more lime juice for brightness.

Part 3: Assembling the Avocado Rice Ball Snacks

1. Set Up Your Station: Have your bowl of cooled seasoned rice, your bowl of avocado filling, and a small bowl of water ready. Also, have a plate with the 2 tablespoons of toasted sesame seeds spread out for coating.
2. Wet Your Hands: Dip your hands into the bowl of water. This is a critical tip that prevents the sticky rice from clinging to your palms and fingers, making the shaping process smooth and easy. Re-wet your hands as needed between forming each rice ball.
3. Form the Base: Scoop about ¼ cup of the seasoned rice into your wet palm and flatten it into a small, even disc.
4. Add the Filling: Create a small indent in the center of the rice disc with your thumb. Spoon about 1 to 1 ½ teaspoons of the avocado filling into this indent. Be careful not to overfill, as it can make sealing the rice ball difficult.
5. Seal the Ball: Gently bring the edges of the rice disc up and around the avocado filling, enclosing it completely. Add a little more rice on top if needed to seal it fully.
6. Shape the Ball: Carefully cup the rice in your hands and gently press and roll it into a firm, compact ball. You can also shape it into the traditional triangular onigiri shape if you prefer. The goal is to make it compact enough that it won’t fall apart.
7. Coat and Finish: Roll the finished rice ball in the plate of toasted sesame seeds, pressing gently so they adhere to the surface. If you’re using nori, you can wrap a small strip around the bottom of the rice ball.
8. Repeat: Continue this process with the remaining rice and filling until you have used all your ingredients. Place the finished avocado rice balls on a serving platter.