1. Heat the oil in a heavy soup pot or Dutch oven. Add the onion and sauté until beginning to brown, seasoning with salt as it cooks.
2. Move the onions to one side of the pot and sear the meat on the other side. Add crushed garlic and mushrooms to the onions and stir.
3. Once the meat has browned, add soy sauce and ale and cook over high heat for two to three minutes. Add water and black pepper. Bring to a boil, then lower heat to a simmer and cook about three hours.
4. Remove the meat from the pot, shred, and return to soup. Add cabbage and cook until cabbage is soft but not falling apart, about 30 minutes. Taste and adjust seasoning as necessary.