Avocado Mango Poke Salad

Name: Avocado-Mango Poke Salad
Ingredients: 2 tbsp. low-sodium soy sauce; 1 tbsp. toasted sesame oil; 1 tbsp. sesame seeds, plus more for garnish; 1 lb. raw sashimi-grade tuna, cut into 1/2 cubes; 2 green onions, thinly sliced; 0.25 c. chopped onion; 0.25 jalapeño, finely chopped; 1 tbsp. finely chopped seaweed, such as wakame or hijiki (optional); 1 avocado, sliced; 1 mango chopped (1 cup)