Crispy Rice:

1. Prepare the Rice Vinegar Mixture: In a small mixing bowl, combine the rice vinegar, sugar, and salt. Stir until dissolved. This mixture seasons the sushi rice.

2. Season the Rice: Pour the rice vinegar mixture over the cooked sushi rice and mix until well combined. Make sure every grain of rice is coated in the mixture.

3. Chill the Rice: Transfer the rice to a baking pan lined with plastic wrap. Gently press the rice to even it out, creating a firm, compact layer. Cover and let it chill in the fridge for at least 4 hours, or preferably overnight. Chilling the rice is crucial for making it firm enough to cut and fry.

4. Cut the Rice: Once the rice is chilled, cut it into 16 rectangles. You can use a sharp knife or even a pizza cutter for this step.

5. Fry the Rice: Heat vegetable oil in a pan over medium heat. The oil should be hot enough for frying, but not smoking. Gently place the rice rectangles in the hot oil and fry until both sides turn a nice golden brown. Remove from the heat and let them cool on a paper towel-lined plate to drain any excess oil. Frying the rice gives it its signature crispy texture.

Spicy Salmon:

1. Prepare the Salmon: Chop the sushi-grade salmon into small pieces. The pieces should be roughly the same size for even mixing.

2. Combine Ingredients: Transfer the chopped salmon to a bowl and combine it with the Kewpie mayo, sriracha, soy sauce, scallion, and sesame oil. Mix well until everything is evenly distributed.

3. Chill: Set the salmon mixture aside in the fridge until ready to use. Chilling the salmon allows the flavors to meld together.

Serving:

1. Assemble: Top each crispy rice rectangle with a slice of avocado, a tablespoon of the spicy salmon mixture, and a slice of jalapeno.

2. Garnish: Sprinkle with black and white sesame seeds.

3. Serve: Serve immediately and enjoy!