over medium-high heat. add meat and brown on all sides.
transfer meat to a bowl. add onion and celery to pan, adding more oil if needed. cook, stirring, over medium heat 5 minutes. stir in mushrooms, carrot and garlic. cook, stirring, 3 minutes. add remaining ingredients except potatoes. add beef.
bring to a simmer. cook, partially covered, 20 minutes, stirring occasionally. add potatoes and return soup to a simmer. cook, partially covered, until potatoes are tender, about 20 minutes. 