Preheat oven to 400°F (200°C). On a baking sheet, toss broccoli florets with 1 tablespoon olive oil, 1/4 tsp salt, and 1/8 tsp black pepper. Spread in a single layer and set aside.

In a large mixing bowl, combine ground chicken, panko breadcrumbs, beaten egg, 3 cloves minced garlic, grated onion, 1/2 tsp salt, 1/4 tsp black pepper, and dried oregano. Mix gently but thoroughly until just combined (do not overmix).

Roll the mixture into approximately 18-20 meatballs, about 1.5 inches in diameter.

Heat 2 tbsp olive oil in a large non-stick skillet over medium-high heat. Add meatballs in a single layer (cook in batches if necessary to avoid overcrowding). Cook for 3-4 minutes per side until nicely browned all over and cooked through, about 12-15 minutes total. While meatballs are cooking, place the baking sheet with broccoli in the preheated oven and roast for 12-15 minutes, or until tender-crisp and slightly charred.

While meatballs and broccoli cook, prepare your rice if not already done. For instant rice, follow package directions.

Once meatballs are cooked, remove them from the skillet and set aside. Reduce heat to medium-low. Add melted butter to the same skillet. Add 4 cloves minced garlic and red pepper flakes (if using). Sauté for 1-2 minutes until fragrant, being careful not to burn the garlic.

Return cooked meatballs to the skillet with the garlic butter sauce. Toss gently to coat. Stir in chopped fresh parsley and chives (if using). Serve immediately with roasted broccoli and cooked rice. Garnish with additional fresh parsley, if desired.