In a large bowl, combine turkey, milk, panko, cheese, dried oregano, basil, salt and pepper. Form into (1-1/2 inch) meatballs.
In an oven-proof skillet over medium-high heat, add 1 tsp canola oil and cook meatballs 8 minutes, turning to brown all sides. Spoon marinara sauce over meatballs and bake for 12-15 minutes until cooked. Assemble sliders now, or place Marinara Meatballs in the refrigerator for up to 3 days.
Assemble sliders:
Re-heat Marinara Meatballs (if using from refrigerator).
Preheat broiler to high.
To each mini-slider bun bottom, place 1 basil leaf, 1 Marinara Meatball with sauce, and top with 2 cheese slices. Place 8 sliders on a cookie sheet and slip under the broiler 1 minute to melt and brown the cheese. Place top of bun and serve. Repeat with remaining 8 sliders.