For the sauce:
1/3 cup extra-virgin olive oil
1 Spanish onion, diced
6 garlic cloves, minced
2 28-ounce cans peeled plum tomatoes
¾ teaspoon kosher or coarse sea salt
For the meatballs:
½ small baguette (6 ounces), crust trimmed
6 tablespoons extra-virgin olive oil
½ large Spanish onion, diced
8 garlic cloves, minced
2 pounds ground lamb
1 pound ground pork
1½ cups grated pecorino Romano cheese, more for serving
1 cup chopped fresh parsley
¾ cup chopped fresh mint
1½ teaspoons freshly ground black pepper
1½ teaspoons kosher or coarse sea salt
¾ teaspoon crushed red pepper flakes
1 cup dry red wine
For the crostini:
½ baguette, sliced on a bias
2 tablespoons extra-virgin olive oil.
1. Prepare sauce: In an ovenproof pot or Dutch oven over medium-high heat, warm oil. Add onions and sauté until soft, about 6 minutes. Add garlic, and cook for 1 minute longer. Stir in tomatoes and salt and reduce heat to medium-low. Simmer sauce, occasionally mashing tomatoes against side of pot with a wooden spoon, until they break down and sauce thickens, about 25 minutes. Let cool slightly.
2. Pass sauce through coarsest disc of a food mill, or purée it until smooth in a food processor or blender. Return sauce to pot.
3. Prepare meatballs: Soak baguette in enough water to cover until soft and falling apart. Squeeze dry. In a very large skillet over medium heat, warm 3 tablespoons oil. Add onions and sauté until translucent but not browned, about 8 minutes. Add garlic, stir well, and turn off heat. Let cool.
4. Heat oven to 325 degrees. In a large bowl, combine lamb, pork, cheese, parsley, mint, pepper, salt, red pepper flakes, onion mixture and bread. Using your hands, mix well. Form mixture into 1¾-inch meatballs.
5. Add remaining oil to pan, and warm it over medium-high heat. Fry meatballs, turning on all sides, until well browned. Transfer meatballs to platters lined with paper towels.
6. Add wine to skillet, and let it simmer for a few minutes, scraping up any browned bits stuck to bottom of pan with a wooden spoon. Pour wine into tomato sauce and add meatballs. Cover pot and bake for 30 minutes.
7. Just before serving, heat broiler. Brush baguette slices with olive oil. Toast them under broiler until golden around edges, about 1 to 2 minutes per side. Serve meatballs with sauce, crostini and extra cheese.