Perfect Lasagna Bolognese

Heat olive oil and 1 tablespoon butter in a large Dutch oven over medium heat. Add pancetta; cook and stir until browned, about 8 minutes. Add celery, carrots, and onion; cook, stirring occasionally, until very soft, about 15 minutes. Stir in beef and pork. Season with salt and pepper. Cook until evenly browned, about 20 minutes.

Pour white wine into the Dutch oven; cook until alcohol evaporates, about 5 minutes. Stir in crushed tomatoes, tomato paste, and sugar. Bring to a simmer; reduce heat to low, cover and simmer Bolognese sauce, stirring occasionally and skimming fat off the surface, about 3 1/2 hours. Stir in beef broth, 1/4 cup at a time, if sauce looks dry.

Stir heavy cream and 1/2 cup milk into the Bolognese sauce; mix well. Cover and cook over very low heat until flavors combine, about 30 minutes.