Cut beef into 3/4 inch pieces, removing fat as desired.
Slice one third of the mushrooms thinly. Chop the remaining mushrooms. Set both aside. Prep the rest of the vegetables.
Heat 1 tablespoon of oil in heavy large pot over medium high heat. Add beef and cook until browned on all sides, stirring frequently. Remove beef to bowl.
Add 1 tablespoon of oil to pot. Stir in chopped onions. Sprinkle with 1/2 teaspoon salt. Cook onions until they are light golden brown and wilted, about 10 minutes. Add minced garlic and cook 1 more minute, stirring frequently.
Add chopped celery, carrots, and parsnips to onion-garlic mixture, stirring well. Cook for five minutes, stirring frequently.
Add chopped mushrooms to vegetable mixture and cook an additional 2 minutes.
Add beef broth and water to pot, stirring to scrape up any browned bits on the bottom. Add bay leaf, thyme, and black pepper to soup mixture. Bring to a boil, then lower the heat to simmer, place the cover a bit ajar, and cook for one hour, stirring occasionally.
Add barley to soup. Cover the pot and cook for 30-45 minutes, until barley is cooked through.
Add tomato paste to soup mixture and stir well to incorporate it. Add sliced mushrooms and cabbage. Simmer for 10 minutes. Taste for seasonings and adjust with salt and pepper.
Sprinkle servings of soup with fresh chopped parsley.