In a small bowl, mix the gluten free breadcrumbs and milk. Let it sit for 5 minutes to soften the crumbs.
In a large mixing bowl, combine the ground beef, ground pork, the soaked breadcrumb mixture, egg, grated parmesan cheese, minced garlic, fresh chopped parsley, salt, and black pepper.
Gently mix everything together using your hands just until combined. Do not overmix to keep the meatballs tender.
Roll the mixture into 1.5-inch balls and place them on a parchment-lined baking sheet.
Bake in a preheated oven at 400 degrees fahrenheit for 20 minutes, or until browned and cooked through.
Serve as an appetizer or drop them into your favorite simmering marinara sauce.