Last Updated on March 11, 2023

Makes 4 Servings
Hands-on time: 15 minutes
Total preparation time: 33 minutes

This dish began as a variation on a French recipe called boeuf a la ficelle (literally “beef on a string), which requires the cook to tie a string around some filet mignon and lower it into a pot of barely simmering broth. I tried it and was stunned by its blandness. It struck me as a scandalous waste of a very expensive cut of meat, and I was ready to junk the whole idea. Then Joanne, my collaborator on this book, noted that though the meat was ruined, the broth was really delicious. So we switched to flank steak (which is much more affordable than filet mignon) and seared it separately. The end result turned out to be a great cold weather dish.

1 medium leek (white part only)
6 cups canned chicken broth or homemade chicken stock
2 medium carrots (about 6 ounces), peeled and sliced 1/2-inch thick
2 medium parsnips (about 10 ounces), peeled and sliced 1/2-inch thick
2 small turnips (about 8 ounces), peeled, quartered, and sliced 1/2-inch thick
2 garlic cloves, sliced (about 2 teaspoons)
1 sprig rinsed and dried fresh thyme or 1 teaspoon dried
1 Turkish bay leaf
2 teaspoons extra virgin olive oil
1 pound beef flank steak
Kosher salt and freshly milled black pepper
1/3 cup sour cream or creme fraiche
1 teaspoon prepared wasabi

Halve the leek lengthwise and cut into 1/2-inch lengths. Rinse in several changes of water and drain well. In a large saucepan, combine the leek with the broth, carrots, parsnips, turnips, garlic, thyme, and bay leaf. Bring to a boil over high heat; reduce the heat to low and simmer until the vegetables are tender, 15 to 18 minutes.

Meanwhile, heat the oil in a large skillet over high heat until hot. Reduce the heat to medium-high and add the beef seasoned with salt and pepper. Saute until well browned on both sides and medium-rare in the center, 8 to 10 minutes total. Remove the beef to a plate; cover loosely with aluminum foil and let rest 5 minutes, then slice thinly against the grain.

Stir together the sour cream, any juices from the beef plate, and the wasabi; add salt and pepper to taste. Discard the thyme sprig and bay leaf; divide the vegetables and broth among 4 soup bowls. Arrange one-fourth of the beef in the center of each bowl and top each portion with a spoonful of the wasabi cream.