How to Make It
Combine rice, kale, 1 tablespoon vinegar, and salt in a bowl; toss to coat.
Combine soy sauce, sesame oil, Sriracha, ginger, and remaining 1 tablespoon vinegar in a large bowl, stirring well with a whisk. Add tuna, cucumber, avocado, and green onion; toss gently to coat.
Divide rice mixture evenly among 4 bowls; top with tuna mixture. Sprinkle evenly with sesame seeds. Serve immediately.