Fill a large Dutch oven or pot halfway with oil and attach a deep-fry thermometer to the side. Heat over medium heat to 350 degrees F.

Meanwhile, mix together the chicken, basil, parsley, Pecorino, egg, 1/4 cup of the panko, 1 teaspoon salt and a few grinds of pepper in a large bowl.

Scoop 1 heaping tablespoon of the chicken mixture and flatten it into a 2-inch circle in your hand. Put 1 mozzarella pearl in the center of the circle. Pat the meat mixture around the cheese to encase it in a ball and set aside on a plate or baking sheet. Repeat with the remaining chicken mixture and mozzarella.

Stir together the Parmesan, 1/2 teaspoon salt and remaining 1 cup panko in a medium bowl.

Working 1 at a time, toss the chicken balls in the panko mixture until completely coated, pressing the panko into the balls with your hands to make sure it sticks.

Fry the balls in batches until deep golden brown and the chicken is cooked through, 4 to 5 minutes. Transfer to a plate lined with paper towels to drain, then sprinkle with more Parmesan. Repeat with the remaining balls, bringing the oil back to temperature between batches if needed. Serve with warm marinara sauce for dipping.