Step 1

In a large nonstick skillet with a lid, stir together 2 cups water, the rice, 1 tablespoon rice vinegar, the sugar and 1 teaspoon salt. Bring to a boil over high heat, then cover, reduce heat to low and cook until rice is tender, 18 to 20 minutes. 

**Alternatively, Do the above in a rice cooker, cook, and spread the cooked rice on a sheet pan, cover and refrigerate until ready to use. 

Step 2

Meanwhile, thinly slice the scallions and cucumbers. In a large bowl, stir together the scallions, tuna, mayonnaise, Sriracha, soy sauce and remaining 2 teaspoons of rice vinegar. Taste and add more Sriracha for more heat. Refrigerate until the rice is ready (or up to 5 days).

Step 3

Sprinkle the cucumbers with a pinch of salt.

Step 4

Now crisp the rice: Make 4 or 5 small holes in the rice in the skillet, then pour the oil down the sides of the pan and into the divots. Increase heat to medium and cook until the rice is browned at the edges, 4 to 7 minutes. (You can lift the rice to check.) If you don’t see oil bubbling in the holes, add a teaspoon or two more oil.

**If you cooked the rice in a rice cooker ahead of time, heat the oil in the nonstick skillet over medium heat and transfer the rice to the skillet. Flatten the rice to cover the bottom of the pan and proceed with crisping the rice. 

Step 5

Divide the rice, crispy side up, among bowls or plates and serve with a scoop of the spicy tuna and the cucumbers.