Season brisket with spices, salt, and pepper.
Sear in olive oil until browned.
Add onions + garlic to slow cooker; place brisket on top.
Whisk tomatoes, broth, collagen, Worcestershire, and tomato paste. Pour over meat.
Cook on LOW 8–9 hours or HIGH 4–5 hours.
Shred brisket and return to sauce. Stir in cream.
Cook pasta; add to sauce.
Serve with parmesan and parsley.