Preheat the oven to 425°F. Line a large rimmed baking sheet with parchment paper and brush it lightly with olive oil.
Combine the panko and milk in a small bowl and let soak for 5 minutes until the crumbs are fully damp.
Stir together the soaked panko, egg, Parmesan, onion, garlic, parsley, oregano, salt, and pepper until evenly combined, breaking up any wet clumps.
Scatter the cold ground beef over the seasoning base and fold with your fingers just until no obvious streaks remain — do not knead or overwork the mixture.
Scoop 18 portions (about 2 tablespoons each) onto the baking sheet. Roll each piece lightly between damp palms until round and leave about 1 inch of space around each one.
Bake for 14 to 17 minutes until the outsides show browned patches and the center of the largest meatball reaches 160°F on an instant-read thermometer. Start checking at 14 minutes.