In a large mixing bowl, combine the ground chicken, breadcrumbs, grated Parmesan cheese, egg, minced garlic, chopped parsley, chopped onion, salt, black pepper, dried oregano, and crushed red pepper flakes.
Mix all ingredients thoroughly using your hands or a spoon until well combined.
Shape the mixture into 1 1/2-inch meatballs, about 16 meatballs in total.
Place the meatballs on a baking sheet lined with parchment paper, making sure they do not touch.
Freeze the meatballs on the baking sheet for 1 to 2 hours, or until solid.
Once frozen, transfer the meatballs to a freezer-safe zip-top bag or airtight container. Label with the date and store in the freezer for up to 3 months.
To cook from frozen, heat olive oil in a large skillet over medium heat.
Add the frozen meatballs to the skillet and cook for 10 minutes, turning occasionally to brown all sides.
Reduce heat to medium-low, cover the skillet, and cook for an additional 8 to 10 minutes, or until the meatballs are cooked through and reach an internal temperature of 165°F (74°C).
Serve immediately with your favorite sauce or side dish.