Melt butter in Dutch oven over medium heat. Cook celery, onion and garlic 5 min. until starting to soften. Stir in root vegetables, sage and salt. Cook 10 min. until root vegetables start to brown.
Stir in wine, if using (if omitting wine, add 1/2 cup (125 mL) broth); scraping bottom of pan to incorporate browned bits into sauce. Stir in tomatoes and broth; bring to a simmer. Reduce heat to medium-low; cover and cook, stirring occasionally, 45 min. Uncover and cook another 15 min. until vegetables are tender and sauce is thickened.
Turn any leftover ragu into a soup by adding more broth and canned white beans.