Perfect Lasagna Bolognese

Name: Perfect Lasagna Bolognese
Ingredients: 1 tablespoon olive oil; 1 tablespoon butter; 0.5 pound pancetta (Italian bacon), diced; 2 cups chopped celery; 1.75 cups chopped carrots; 1.25 cups chopped onion; 1.5 pounds coarsely ground chuck; 1 pound coarsely ground pork shoulder; salt and ground black pepper to taste; 1 cup dry white wine; 1.5 cups no-salt crushed tomatoes in puree; 2 tablespoons tomato paste; 1 teaspoon white sugar; 0.5 cup beef broth; 0.5 cup heavy whipping cream; 0.5 cup whole milk; 5 tablespoons butter; 0.25 cup all-purpose flour; 4 cups whole milk; 1 bay leaf; 0.5 teaspoon salt; 0.25 teaspoon freshly grated nutmeg; 8 (9x13-inch) fresh lasagna sheets; 2 cups finely grated Parmesan cheese, divided