In a large bowl, combine the ground chicken, panko, egg, green onions, garlic, ginger, fish sauce, lime zest, salt, pepper, and cilantro. Gently mix with your hands or a fork until everything is evenly incorporated—try not to overwork the meat or the meatballs can get dense.

Wet your hands slightly and form the mixture into 1 to 1 1/4-inch meatballs. Place them on a baking sheet.

Heat a large skillet over medium heat and add a splash of oil. Working in batches, brown the meatballs on all sides—about 6–8 minutes total.

In the same skillet, lower the heat and add a touch more oil if needed. Sauté the chopped onion for 3–4 minutes until translucent. Add the garlic and sauté 30 seconds more. Stir in the red curry paste and cook for 1 minute.

Pour in the coconut milk, broth, and brown sugar. Stir to combine and bring to a gentle simmer. Add fish sauce and lime juice, adjusting for salt, sweetness, or tang.

Gently nestle the browned meatballs into the simmering curry. Cover and let them cook for 8–10 minutes, or until the meatballs reach 165°F internally and the sauce has slightly thickened.

Spoon the Thai chicken meatballs and coconut curry over steamed jasmine rice or rice noodles. Garnish with fresh basil or cilantro, lime wedges, and toasted peanuts if desired.