Pastitsio For 20

Ingredients

• 10 Tb olive oil , divided
• 4 C chopped onions
• 4 large garlic cloves , chopped
• 2 lb ground beef , lean (15% fat)
• 2 tsp dried oregano
• 1½ tsp salt
• 1 tsp ground black pepper
• 2 cans petite diced tomatoes in juice , 14 1/2-ounce each
• 1 C beef broth
• 6 Tb tomato paste
• 1½ tsp ground cinnamon
• 1 tsp ground allspice
• ½ tsp ground nutmeg
• ¼ tsp ground cloves
• 3 large eggs , beaten to blend
• 1½ lb macaroni pastitsio , no. 2 perciatelli (long hollow Greek pasta)
• 3½ C grated Parmesan cheese , about 10 ounces, divided
• Béchamel Sauce