Heat remaining oil in a large skillet over high. Add tuna , onion, pineapple, chilies, rice vinegar, and coconut sugar to the skillet; cook until everything is heated through and the onions are translucent. Turn off the heat and stir in the cilantro and sesame seeds.
Fill tortillas with desired amount of tuna taco mixture, top with avocado, and enjoy!
Keywords: tuna, tacos, seafood, healthy tacos, main meal, lunch, dinner