In a large bowl, combine ground chicken, breadcrumbs, Parmesan cheese, egg, minced garlic, chopped parsley, chopped onion, salt, black pepper, dried oregano, and crushed red pepper flakes.
Mix all ingredients thoroughly until well combined.
Shape the mixture into 1-inch meatballs and place them on a baking sheet lined with parchment paper.
If freezing for later use, place the baking sheet with meatballs in the freezer for 1-2 hours until firm, then transfer the meatballs to a freezer-safe bag or container. Label and store for up to 3 months.
To cook fresh or frozen meatballs, heat olive oil in a large skillet over medium heat.
Add meatballs to the skillet and cook for 10-12 minutes, turning occasionally, until browned on all sides and cooked through (internal temperature should reach 165°F).
Remove meatballs from the skillet and serve immediately or add to your favorite sauce or dish.