Meatball Sliders

Step 1: In a large bowl mix together the first 11 ingredients (meats - pepper, but using only 1/4 cup parsley and six tablespoons of the cheese - saving remainder of the parsley and cheese for serving). Form into 18 two-inch meatballs.

Step 2: In a skillet heat the vegetable oil over medium high heat. Working in batches fry meatballs until brown, transferring them to a plate. Pour off drippings and then reduce heat to medium. Add the olive oil to the skillet.

Step 3: Stir in the next 4 ingredients (onion - fennel seeds) and saute until onion browns (5 minutes). Stir in tomatoes and bring to a boil, scraping up the brown bits. Reduce heat to low, cover and simmer for 30 minutes, stirring occasionally. Puree sauce in a processor or blender until almost smooth (or use an immersion blender while sauce is in pan); return to skillet. Add meatballs and simmer until meatballs are heated through (30 minutes).

Step 4: ***Do ahead -- meatballs and sauce and be made one day ahead, cover and chill.

Step 5: To serve: place argula leaves on bottom of each roll, if using leaves, top with 1 meatball and some sauce and sprinkle with remaining parsley (2 T) and 2 tablespoon cheese. Cover with tops of rolls.