Short Rib Soup with Mushrooms & Pearl Couscous

I made a batch of Red Wine Braised Shortribs, and I saved the vegetables that were used in the braising liquid. With the leftovers, I made this delicious soup.
I thank Chef Hubert Keller for sharing this recipe on his television show. It's delicious!
To find the Red Wine Braised Short Rib Recipe click here: http://www.keyingredient.com/recipes/6818032/red-wine-braised-short-ribs/