Just made this off the top of my head and inhaled it, writing it down so I don't forget:

Poki Poki

1/2 lb raw Saku block Tuna (Yellowfin Ahi) cut in 1/2" cubes
1 tb diced sweet yellow onion (or red onion)
1 tb Ponzu (lime or lemon juice would probably work)
1 tb diced fresh garlic tops (green onion would work, but the garlic tops are amazing)
1 tsp Sriracha Sauce
1 tsp Sambal Olek
1 tsp toasted sesame seeds (black or white don't matter)
1 tb soy sauce
1 tb sesame oil (spend the extra and get TOP shelf sesame oil [$10-15] and keep in in your fridge)

Mix all ingredients together in a small container, cover and chill for 1-2 hours before serving.