Thaw tuna according to package directions and cut into ½-inch cubes. Add cubed tuna to a medium bowl with 2 tablespoons soy sauce, 1½ teaspoons rice vinegar, 1 teaspoon sesame oil, ¼ cup sliced green onion, ¼ teaspoon sesame seeds and a pinch of red pepper flakes. Refrigerate to marinate for 20 minutes.

While poke is marinating, add avocado, juice of ½ lime and ¼ teaspoon salt to a small bowl. Mash until well combined and adjust salt, as needed.

Make spicy mayonnaise by adding 3 tablespoons mayonnaise and 1 tablespoon sriracha to a small bowl and whisking until well incorporated.

To make the dish, add a slice of toasted bread to a plate. Top with a layer of avocado spread. Spoon on marinated poke mixture. Drizzle with spicy mayonnaise. Sprinkle on extra sesame seeds and microgreens to garnish and serve.