In a large bowl, combine ground chicken, breadcrumbs, Parmesan, the beaten egg, oregano, mint, garlic, and onion. Season with salt and pepper. Mix gently and form into 1-inch meatballs.
Heat a large skillet over medium-high heat. Add olive oil and sear the meatballs for 2-3 minutes per side until golden brown. Remove and set aside.
Lower the heat to medium, then pour in white wine to deglaze the pan. Scrape up browned bits and reduce the wine by half, about 2 minutes.
Stir in chicken broth, lemon juice, and zest. Bring to a gentle simmer, seasoning with salt, pepper, and optional red-pepper flakes.
Add orzo to the simmering liquid. Cook for 8-10 minutes, stirring occasionally, until the orzo is tender and absorbs most of the liquid.
Return meatballs to the skillet, nestling them into the orzo. Cover the pan and cook for 5 more minutes, ensuring the meatballs reach an internal temperature of 165°F.
Let the dish rest for 3 minutes before serving. Garnish with fresh parsley and serve immediately.