In a large bowl, gently combine the ground chicken, almond flour, two-thirds of the grated Parmesan cheese, the egg, minced garlic, Italian seasoning, salt, and pepper. Mix lightly with your hands until just combined – try not to overmix, as this keeps the meatballs tender.
Lightly wet your hands to prevent sticking, then roll the mixture into about 30-36 meatballs, roughly 1½ inches each. Place them on a tray lined with waxed paper and pop them in the refrigerator for 30 minutes. This helps them firm up and hold their shape during cooking.
Preheat your oven to 375°F (190°C). Heat one tablespoon of olive oil in a large oven-proof skillet over medium heat. Working in batches, brown about half of the meatballs on all sides until nicely golden. They don't need to be cooked through at this stage. Transfer the browned meatballs to a plate. Repeat with the remaining olive oil and meatballs.
Once all meatballs are browned, return them all to the skillet in a single, even layer. Pour your delicious roasted tomato sauce evenly over the meatballs, then generously sprinkle with the shredded mozzarella and the remaining Parmesan cheese.
Transfer the skillet to your preheated oven and bake for 25 to 30 minutes, or until the cheese is beautifully melted, bubbly, and slightly golden.
Carefully remove the skillet from the oven. For a fresh touch, sprinkle with chopped parsley or basil before serving. These flavorful meatballs are perfect on their own or with zucchini noodles!