Add butter to stock pot on medium high heat. Add the onions, celery, carrots, parsnips, rutabaga, leeks and butternut squash. Cook covered until softened, about 8 minutes.
Stir in the white wine, garlic, rosemary and sage. Cook uncovered for about 2-3 minutes.
In a separate saute pan, brown the beef and then transfer to a slow cooker.
Transfer the onion mixture to a 6 quart slow cooker.
Stir in the Worcestershire, red potatoes, beef stock, flour and parsley. Taste and adjust seasoning if necessary.
Cook 7-8 hours on low or 4-5 hours on high, or until the potatoes have softened.
Serve with extra parsley for garnish and white cheddar.