In a large saucepan, brown the meat and onions in the duck fat. Season with salt and pepper. Add the garlic and cook for 1 minute. Sprinkle with the flour and stir to blend. Add the broth and barley. Bring to a boil. Cover and simmer for 30 minutes. Add the carrots, celery and potatoes. Bring to a boil and simmer, covered, for another 30 minutes. Add the corn and cook for 5 minutes. Adjust the seasoning. Add broth as needed.