- Melt butter in a large saucepan over medium heat. Add celery, carrots, onion, garlic, and salt; cook stirring occasionally until tender, about 5 min.
- Remove sausages from casings and add to pan along with ground beef. Use a fork to break up meat; stir continously over medium heat until no longer pink, about 5 min. Add milk.
- Gently boil, uncovered, stiring occasionally for 5 min.
- Add tomatoes, mashing with a potato masher to break them up. Add parsley and chili flakes, if using mild sausage.
- Simmer, uncovered, stirring occasionally 30 min or until thickness desired.
Cooking Tip: When cooking pasta, use a big pot, salt water generously and don’t add oil to the water.