In large pot, heat olive oil over medium heat. Add onion and garlic; cook and stir until crisp tender, about 3-5 minutes. Add carrots; cook and stir for 2-3 minutes longer. Add potato wedges and beef broth; cover and bring to a simmer.
Meanwhile, cut roast beef into 1" chunks; add to soup along with gravy from pkg, thyme, and beer. Bring to a boil; reduce heat and simmer for 10-15 minutes until beef is hot and stew is slightly thickened. In small bowl, combine cornstarch and water and blend well. Stir into stew; cook and stir for 4-5 minutes longer until stew is thickened. Serves 6.