In a medium pan over medium heat, warm olive oil. Add chopped celery, carrot, and onion, seasoning with kosher salt and black pepper. Sauté for about 5 minutes until the vegetables are softened and fragrant, stirring occasionally.

Stir in finely chopped garlic cloves and cook for an additional minute until aromatic but not browned. Remove from heat.

In the same pan, add ground beef and cook over medium heat for about 5-7 minutes. Drain any excess fat.

Transfer the cooked meat and vegetable mixture into the slow cooker. Add tomato paste, dry red wine, whole milk, and crushed tomatoes. Stir in oregano, basil, and thyme.

Cover and cook on low for 4-6 hours until thick and aromatic.

Prepare fettuccine according to package instructions about 10-15 minutes before serving. Cook until al dente, then drain.

Plate fettuccine and ladle the Bolognese sauce over the top. Garnish with grated Parmesan cheese, fresh basil, and parsley.