To prepare sauce, heat a large nonstick skillet over medium-high heat. Coat pan with cooking spray. Add 1 cup onion; sauté for 3 minutes. Add 3 garlic cloves, and sauté 1 minute. Add tomato paste; cook 1 minute. Stir in 1/4 teaspoon salt and broth. Cook 4 minutes. Stir in the tomatoes. Reduce heat, and simmer 45 minutes, stirring occasionally.
To prepare meatballs, place bread in a food processor, and process until fine crumbs measure 1/2 cup. Combine the breadcrumbs, sausage, 1/2 cup onion, and next 8 ingredients (through sirloin) in a bowl. With wet hands, shape sirloin mixture into 32 meatballs. Place meatballs on a broiler pan. Broil 15 minutes or until done. Add meatballs to sauce; simmer 15 minutes. Sprinkle with 1/2 cup parsley and 1/3 cup basil. Serve over spaghetti. Sprinkle with cheese; garnish with parsley sprigs, if desired.
Wine note: Spaghetti and Meatballs is terrific with red or white wine as long as the wine has good acidity to mirror that of the tomatoes and act as a counterpoint to the meatballs. Because our recipe has fresh herbs, I prefer white wine with the dish--in particular, an herbal dry white from southern Italy such as Feudi di San Gregorio Greco di Tufo 2004 ($22). -Karen MacNeil