In a large bowl, combine ground chicken, egg, breadcrumbs, Parmesan, onion, garlic, Italian seasoning, paprika, salt, and pepper.
Mix gently until just combined—do not overmix.
Roll into evenly sized meatballs (about 1½ tablespoons each).
Heat olive oil in a large skillet over medium heat.
Brown meatballs on all sides, about 6–8 minutes total. Remove and set aside.
In the same skillet, melt butter over medium heat.
Add sun-dried tomatoes and cook for 1 minute.
Pour in chicken broth and simmer 2–3 minutes, scraping up browned bits.
Stir in heavy cream, Parmesan cheese, and red pepper flakes if using.
Return meatballs to the skillet and simmer gently for 10–12 minutes, until cooked through and sauce thickens.
Taste and adjust seasoning.
Remove from heat and rest 5 minutes before serving. Garnish as desired.