Preheat your oven to 400°F (200°C). Line a large baking tray with parchment paper or aluminum foil, then brush lightly with olive oil to prevent sticking and encourage browning.
In a large bowl, add the ground chicken, Panko breadcrumbs, egg, diced red onion, minced garlic, chopped red chilies, parsley, coriander, kosher salt, black pepper, cayenne pepper, soy sauce, and olive oil. Using your hands, gently mix the ingredients until evenly incorporated. Be careful not to overwork the mixture to ensure the meatballs remain tender.
Lightly oil your hands and shape the mixture into approximately 28–30 bite-sized meatballs. Arrange them evenly on the prepared baking sheet, allowing space between each for even cooking.
Place the tray in the preheated oven and bake for 28–30 minutes, or until the meatballs are golden brown and cooked through.
While the meatballs are baking, prepare the sauce. In a medium mixing bowl, combine sweet chili sauce, soy sauce, peanut butter, and crushed red pepper flakes. Stir well until smooth and cohesive.
Once the meatballs are out of the oven, let them rest for 5–10 minutes. Then, transfer them to a skillet over low heat. Spoon a few tablespoons of the sauce over the meatballs and gently toss to coat them evenly. Once glazed, remove from heat.
Serve warm with any remaining sauce on the side for dipping, if desired.