Warm 1 tablespoon of oil in a large soup pot over medium-high heat. Season steak generously with salt and pepper. When oil is hot, add half of the steak and sauté until browned, but not cooked through, about 3 minutes. Remove steak from the pot and set it aside. Repeat with another tablespoon of oil and the remaining steak.
Reduce heat to medium. If there is not about a tablespoon of oil left in the pot, add more as needed. Sauté onions in oil until translucent, about 5 minutes. Add mushrooms and cook, stirring frequently, until they have browned slightly and released their juices, about 5 minutes. Add garlic and thyme and cook for another minute.
Stir in water and Kitchen Accomplice Beef Broth Concentrate or Beef Bone Broth Concentrate, then add green beans and potatoes. Bring to a simmer and cook until potatoes are tender, 15 to 20 minutes. Add the reserved steak and Worcestershire sauce and simmer another 5 to 7 minutes.
Season the steak and potato soup to taste with salt and pepper and serve in warm bowls.