Preheat your oven to 400°F (200°C) and lightly grease a baking dish with olive oil.
In a large bowl, combine the lean ground turkey, egg white, rolled oats, minced garlic, and chopped fresh basil. Season with a pinch of salt and pepper.
Mix the ingredients thoroughly until evenly combined, then form the mixture into small meatballs, about the size of a golf ball.
Place the meatballs in the prepared baking dish and spoon the marinara sauce evenly over the top, ensuring each meatball is well-covered.
Sprinkle the shredded or sliced provolone cheese over the sauced meatballs.
Bake in the preheated oven for 20-25 minutes or until the meatballs are cooked through and the cheese is melted and slightly golden.
Remove from the oven and let rest for a few minutes before serving, enjoying the warm, comforting flavors.