For the tomato sauce: Heat the olive oil in a medium skillet over medium-high heat. Add the onions and cook until beginning to sweat, 3 to 4 minutes. Add the garlic and cook for another minute. Add the tomatoes and half of the basil and cook for about 6 minutes, until the tomatoes begin to break down.
Transfer the sauce to a blender, add the remaining basil and the butter, and puree until smooth. Add salt and pepper to taste.
For the meatballs: In a large bowl, combine the lamb, ricotta, Parmesan, eggs, nutmeg, salt and some pepper. Divide into golf-ball-size meatballs and dust with flour.
Heat some vegetable oil in a large skillet over medium-high heat. Add the meatballs and fry until golden brown all over, 4 to 5 minutes. Add the tomato sauce; finish cooking the meatballs in the sauce.
Serve garnished with bitter greens and shaved Parmesan.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.