1. In a large bowl, combine first 6 ingredients (through pine nuts), 2 tablespoons Parmesan, and pepper. Form into 24 (1 1/2-inch) meatballs.
2. Heat 1 tablespoon oil in medium skillet over medium-high heat; brown meatballs in 2 batches (adding the remaining oil for second batch), turning after 3 minutes; transfer to a plate.
3. Add kale and sauce to pan; bring to simmer. Place meatballs in skillet; simmer, uncovered, until cooked through and sauce is reduced (about 10 minutes), stirring occasionally. Sprinkle with remaining Parmesan; serve with a slice of crusty bread, if desired.