In a large bowl, combine the drained tuna, breadcrumbs, green onions, red bell pepper, egg, soy sauce, sesame oil, garlic powder, onion powder, salt, and pepper. Mix until well combined.
Form the mixture into patties, about 2-3 inches in diameter. You should get around 6-8 patties.
Heat the vegetable oil in a large skillet over medium heat. Once hot, add the tuna patties to the skillet, cooking in batches if necessary. Fry for about 3-4 minutes on each side, or until golden brown and crispy.
While the patties are cooking, prepare the Sriracha mayo by mixing the mayonnaise, Sriracha, and lime juice in a small bowl. Adjust the Sriracha to your preferred spice level.
Once the patties are cooked, remove them from the skillet and place them on paper towels to drain excess oil. Serve warm with the Sriracha mayo on the side.