The hardest part of this soup is slicing the steak into thin, thin slices--but you can skip that step if you buy a package of presliced "beef for stir-fry" from the supermarket or sliced beef for bulgogi from an Asian market.
3 tablespoons cooking oil
1 pound sirloin steak, cut into 1/8-inch thick slices about 1 1/2 inches long and 3/4-inch wide, or 1 pound presliced beef (see headnote)
1 1/4 teaspoons salt
1 large onion, chopped
1 pound baking potatoes (about 2), peeled and cut into 1-inch chunks
1/2 pound green beans, ends trimmed
2 cups water
1 quart canned low-sodium chicken-broth or homemade stock
1/4 teaspoon fresh-ground black pepper
2 teaspoons Worcestershire sauce
How to Make It
In a large pot, heat 1 tablespoon of the oil over moderately high heat. Add half the steak and cook, stirring frequently, until well browned, about 2 minutes. Remove the steak with a slotted spoon. Repeat with another tablespoon of oil and the remaining steak. Remove the steak from the pot and toss all of the steak slices with 1/4 teaspoon of the salt.
Reduce the heat to moderately low and add the remaining tablespoon of oil to the pot. Add the onion and cook, stirring occasionally, until translucent, about 5 minutes.
Add the potatoes, green beans, water, broth, the remaining 1 teaspoon salt, and the pepper to the pot. Bring to a boil, scraping the bottom of the pot with a spoon to dislodge any brown bits. Reduce the heat and simmer until the potatoes are tender, about 15 minutes. Return the steak and any juices to the soup and stir in the Worcestershire sauce.
Wine Recommendation: If the steak and potatoes were on your plate, a Napa Valley cabernet sauvignon would be the obvious choice. It's the perfect pick here as well, but stay with an easy-drinking, light-tannin version for the best match.
Notes: Make sure the steak is well browned before removing it from the pot; those brown bits left on the bottom are essential for flavoring the broth.