Chop guanciale and heat a dutch oven over medium heat. Sweat guanciale for 5-10 minutes until rendered and golden.
Add chopped onion, celery, carrot, and diced garlic and stir to combine. Cook for 5-10 minutes until softened.
Add ground beef and cook until browned, stirring to combine. Add wine and cook until evaporated.
Add tomato passata and cover. Cook for 2 hours until thick, flavorful, and rich in color. After it's cooked, add milk and season with salt and pepper to your taste.
Heat a stock pot of water over medium-high heat. Salt water generously.
Cook bucatini for 7-10 minutes (according to package directions for al dente) and plate.
Top with bolognese sauce, fresh basil, and fresh parmesan.