Swedish Meatball Pasta Bake

Name: Swedish Meatball Pasta Bake
Cuisine: European
Ingredients: 1 and 1/4 cups plain panko bread crumbs; 4 tablespoons butter; 2/3 cup yellow onion, finely chopped; 2 teaspoons salt; 1/2 teaspoon pepper; 1/2 teaspoon ground allspice; 1/4 teaspoon nutmeg; 3 cloves of garlic, minced; 2/3 cup milk; 2 eggs; 1 pound ground beef (I used 85/15.); 1 pound ground pork; 3 tablespoons oil; 2 cups shell pasta; 6 tablespoons butter; 1/4 cup plus 3 tablespoons all-purpose flour; 4 cups beef broth (I used low sodium, equivalent to a 32 ounce box.); 1/2 cup water; 1 tablespoon Worcestershire sauce (See Note below.); 3 tablespoons fresh parsley, finely chopped; 1/2 cup heavy cream; 1 tablespoon salt (See Note below.); 1/2 teaspoon black pepper