Place the short ribs, salt, pepper, flour and spices in a large mixing bowl then place a lage piece of plastic wrap over the top and give it a good shake to dust and season the ribs.
In a large skillet over medium high heat, brown short ribs on all sides, about 2 minutes per side, until brown. Brown in batches to avoid overcrowding the pan.
Place the onions, celery and carrots down on the bottom of the slow cooker then place the browned short ribs on top of the veggies. Pour the beef stock and pomegranate juice into the slow cooker and add the bay leaf and beets. Put a lid on the pot and cook for 6 hours on high, 8 on low.
About 10 minutes before you are ready to serve, make the Creamy Sage Polenta.