Position a rack in the center of the oven and preheat to 400°F. Line a rimmed baking sheet with parchment paper.
In a large bowl combine the ground chicken (or turkey), panko, egg, chopped green onions, chopped cilantro (if using), grated ginger, chopped garlic, 1 tablespoon soy sauce, 2 teaspoons sesame oil, and 1 teaspoon sriracha.
Use a fork to break up the egg yolk and gently mix until ingredients are just combined; switch to your hands and lightly mix if needed. Do not overwork the mixture.
Scoop the mixture by 1-tablespoon portions and roll into 1 to 1½-inch meatballs (about 18–20 total). Place them on the prepared baking sheet, spacing them slightly apart.
Brush the tops and sides of the meatballs with canola oil. Bake until an instant-read thermometer inserted into a meatball registers 165°F, about 10 minutes.
While the meatballs bake, make the sauce: in a medium saucepan whisk together 2/3 cup water, 1/3 cup soy sauce, 1/4 cup creamy peanut butter, 3 tablespoons honey, 1 tablespoon rice vinegar, 1 clove minced garlic, 1 teaspoon grated ginger, and 1 teaspoon sriracha.
Heat the sauce over medium-high, bringing it to a boil while whisking; let it bubble 30 seconds to 1 minute until smooth and slightly reduced, then stir in 1 teaspoon sesame oil. Taste and adjust seasoning if desired, then remove from heat to cool and thicken slightly.
Serve the meatballs over brown or white rice with steamed or fresh vegetables. Drizzle generously with the peanut-sesame sauce and garnish with sesame seeds, extra green onions, and cilantro if desired.