TO MAKE CUPS: Preheat oven to 425ºF. Line a baking sheet with parchment. With a pencil, draw 3” circles on the parchment. Spread 2 tsp of grated Parmesan to fill each circle. Bake for 2-3 minutes or until just lightly golden. Remove from oven and allow to cool 1-2 minutes.
To make bowls, carefully lift each warm circle off the parchment with a spatula and press into a mini-tarlet pan to form a cup. Allow to cool.
TO MAKE FILLING: In a large fry pan over medium-high heat, sauté pork and onions, breaking up with the side of a spoon to make a small crumble. Add oregano, basil, parsley and continue until pork is cooked through. Stir in tomato sauce and season with salt and pepper to taste.
TO ASSEMBLE: Into each Parmesan cup, add a few arugula leaves and top with a Tbsp of pork mixture.