To begin, prepare the gyoza dipping sauce. In a small bowl, whisk together the soy sauce (or coconut aminos), rice wine vinegar, sesame oil, garlic, ginger, sriracha, sesame seeds, and green onions if using. Set aside.
Next, bring a large pot of water to a boil and prepare the cabbage. Working in batches, carefully drop 4–5 napa cabbage leaves into the boiling water and blanch for 1–2 minutes, just until softened and pliable. Remove immediately and transfer to a paper towel-lined surface to cool. Repeat until all of the cabbage leaves are blanched.
Once the cabbage is ready, make the filling. Heat 1 teaspoon of the avocado oil in a large skillet over medium-high heat. Add the ground turkey, carrots, finely chopped mushrooms, dark soy sauce, and Chinese five spice. Cook, breaking the turkey into small pieces, until fully cooked through and evenly seasoned. Stir in the cooked rice and scallions, then remove the skillet from the heat.
To assemble the rolls, layer two cabbage leaves slightly overlapping on a flat surface. Place a heaping spoonful of the filling (about 2–3 tablespoons) near the stem end of the cabbage. Fold the cabbage over the filling, tuck in the sides, and roll tightly, similar to a burrito. Repeat with the remaining cabbage leaves and filling.
Finally, cook the rolls. Heat a large skillet over medium heat and add the remaining avocado oil. Place the cabbage rolls seam-side down in the pan and cook undisturbed for 2–3 minutes, until the bottoms are golden and crisp. Carefully flip and cook for another 2 minutes on the other side. Repeat with remaining rolls as needed. Serve warm with the prepared gyoza dipping sauce and enjoy.