Spicy Tuna and Avocado Cucumber Sushi Bites

Light and healthy spicy tuna 'sushi' with seasoned tuna on cucumber slices along with cool and creamy avocado! Toss 1/2 pound ahi tuna (sushi-grade), finely diced with the mixture of 1 tbsp soy sauce, 1 tsp sriracha (or to taste), 2 tsp mirin (optional), 2 tbsp green onions, finely sliced, 1/2 tsp toasted sesame oil and 2 tsp black sesame seeds, toasted (optional) and place on thinly sliced cumbers and avocados and enjoy!