To prepare short ribs, preheat oven to 350°. Season beef ribs with salt and pepper. Heat canola oil in a large frying pan over medium-high heat. Brown short ribs on all sides.
Spray roasting pan with non-stick spray. Transfer ribs to roasting pan and set aside. To the hot frying pan, add onions, celery, carrots and bay leaf. Lower heat to medium and stir mixture until onions are translucent and golden in color. Add garlic and balsamic vinegar. Deglaze the pan, scraping up brown bits that stuck to the bottom. Add wine and continue to stir.
Pour in Pom juice and worcestershire sauce. Stir to combine. Pour mixture over short ribs in roasting pan. Be sure ribs are nestled in liquid. Cover pan tightly with foil and bake for 2 hours until tender. Uncover for 15 to 20 minutes to brown.
Meanwhile, to prepare the butternut squash, spray a shallow sheet pan with non-stick spray. Spread out cubed squash in one layer on the prepared pan. Sprinkle with chili powder, allspice, cumin, cinnamon, salt and pepper. Drizzle with olive oil, then toss with your hands to combine seasoning and oil, then spread evenly on sheet pan. Roast in 350° oven for 30 minutes.