Rinse the sushi rice under cold water until the water runs clear.
Combine the rinsed rice and 1 1/4 cups water in a medium saucepan and bring to a boil over medium-high heat.
Once boiling, reduce heat to low, cover, and simmer for 15 minutes until water is absorbed and rice is tender.
Remove from heat and let rice sit, covered, for 10 minutes.
In a small bowl, whisk together rice vinegar, sugar, and salt until sugar dissolves.
Gently fold the vinegar mixture into the cooked rice and let cool to room temperature.
Pat the ahi tuna steak dry with paper towels and season lightly with salt.
Heat 1 tablespoon vegetable oil in a skillet over medium-high heat.
Sear the tuna for about 1 to 1 1/2 minutes on each side for medium-rare, or until desired doneness.
Remove tuna from skillet and let rest for 5 minutes, then slice into thin strips.
In a small bowl, whisk together soy sauce, sesame oil, grated ginger, honey, and sriracha sauce to make the dressing.
Divide the sushi rice evenly between two bowls.
Arrange sliced seared tuna, diced cucumber, shredded carrots, avocado slices, and green onions on top of the rice.
Drizzle each bowl with the sesame soy dressing.
Sprinkle toasted sesame seeds and nori strips over the bowls before serving.