Korean Rice Cakes with Beef, Cabbage, and Chili Sauce

8 ounces fresh or thawed frozen tteok (see note)
4 ounces beefsteak, such as chuck or sirloin, very thinly sliced
1/2 teaspoon soy sauce
2 teaspoons sesame oil
2 cloves garlic, minced
1 small onion, thinly sliced
2 cups green cabbage, cut crosswise into large pieces (optional)
1 to 2 tablespoons gochujang (Korean chile paste)
1 to 2 teaspoons sugar
2 scallions, cut into 1-inch batons
Sesame seeds

Soak tteok in cold water to cover while preparing the other ingredients, about 10 minutes. Drain on paper towels.

Combine beef with soy sauce, 1 teaspoon sesame oil and garlic.

Heat a wok or skillet over high heat until very hot. Add beef mixture and stir-fry just until lightly browned, 1 minute. Add onion, scallions, and cabbage, if using, and stir-fry until crisp-tender, 2 to 3 minutes.

Add gochujang and mix. Add about ? cup water, remaining teaspoon sesame oil, sugar and tteok. Mix and let simmer until sauce is thick and tteok is soft, adding water a little at a time as needed. Adjust seasonings with sugar and gochujang.

Mix in scallions and serve hot, sprinkled with sesame seeds.

Tip:
Tteok (Korean rice cakes, also spelled dduk or toppoki) are available in Asian markets. For this dish, the traditional shape is long cylinders; cut them crosswise in half before cooking. If using dried tteok, cook according to package directions and do not soak.