In a large mixing bowl, combine ground chicken, panko breadcrumbs, grated Parmigiano-Reggiano, beaten egg, minced garlic, chopped parsley, Italian seasoning, onion powder, salt, and black pepper. Gently mix with clean hands just until incorporated (do not overmix to keep them tender).

Using a 1.5-tablespoon cookie scoop, portion out the mixture and roll between oiled palms into 16 evenly sized round meatballs. Place on a parchment-lined plate.

Heat 2 tablespoons of extra virgin olive oil in a large deep cast-iron or heavy skillet over medium-high heat until shimmering.

Add meatballs in a single layer with space between each. Sear undisturbed for 3-4 minutes until a deep golden-brown crust forms on the bottom, then turn with tongs and sear the remaining sides for another 3-4 minutes (they do not need to be cooked completely through yet). Transfer seared meatballs to a clean plate.

Lower heat to medium. Melt 2 tablespoons of unsalted butter in the same skillet, scraping up any delicious browned caramelized fond from the bottom. Add the minced garlic and sauté for 60 seconds until intensely fragrant.

Pour in the chicken bone broth, scraping the bottom of the pan, and bring to a gentle simmer for 2 minutes to reduce slightly. Lower heat to medium-low and pour in the heavy whipping cream.

Whisk in the grated Parmigiano-Reggiano cheese in handfuls until completely melted and smooth. Season with salt, black pepper, and optional red pepper flakes.

Return the seared meatballs along with any accumulated resting juices back into the skillet. Spoon the bubbling cream sauce generously over each meatball.

Simmer gently uncovered over low heat for 5-6 minutes until sauce thickens to coat the back of a spoon and meatballs register 165°F (74°C) internally on an instant-read thermometer.

Remove skillet from heat. Garnish with fresh chopped parsley and extra grated parmesan. Serve immediately hot straight from the skillet over ribbons of buttery fettuccine or with warm artisan bread!