Preheat the oven to 375ºF.
In a large bowl, combine turkey, milk, egg, panko, parmesan cheese, dried oregano, basil, black pepper and salt. Form into 1-1/2 inch meatballs.
In an oven-proof skillet over medium-high heat, add olive oil and cook meatballs for 6-8 minutes, turning to brown on all sides. Spoon marinara sauce over meatballs and bake for 10- 12 minutes or until cooked through.
To each mini-slider bun bottom, place 1 basil leaf, 1 meatball with sauce, and top with 1 fresh mozzarella cheese slice. Place sliders on a cookie sheet and slip under the broiler for 1 minute to melt and brown the cheese. Top with bun and serve.