Make the panade: To a small bowl, add breadcrumbs and milk. Let sit for a minute until the milk is absorbed, then mash until smooth.
Add the panade, ground chicken, and all the other ingredients (except feta cheese) for the meatballs to a large mixing bowl. Please add salt to your liking, it's a personal preference. I prefer well-salted foods, but your preferred salt levels may be different.
Mix well for about 5 minutes using either your hands or using a stand mixer fitted with a paddle attachment. In the beginning, the mixture may seem too loose but after some time it should nicely hold its shape. When the meat mixture is ready, gently mix in feta cheese.
Scoop the meat mixture onto a baking sheet lined with parchment paper. Roll the balls between your hands.
Cook meatballs until the internal temperature reaches 165°F (74°C).
In a pan: heat frying oil in a large frying pan over medium heat. Add the meatballs about 1 - 1 1/2 inches (4cm) apart. Cook until browned on all sides and cooked through in the middle.
In the oven: Preheat the oven to 425°F (220°C). Place the meatballs on a baking sheet lined with parchment paper, they should be spaced apart. Bake for 13-15 minutes or until internal temperature reaches 165°F (74°C). The baking time may vary depending on the oven and the size of the meatballs.
In an air fryer: cook the meatballs in the air fryer for about 10 minutes at 425°F (220°C). Please note that this recipe was tested in a countertop oven with an air fryer setting (in an air fryer basket) and I feel that it cooks food more slowly than regular smaller air-fryer models. Please adjust the cooking time to your appliance.
Enjoy!