October Cooking - Beef and Bok Choy Stir Fry

1 lb. beef steak (top round, flank, or sirloin)
1 tablespoon soy sauce
1 head Bok Choy
4 carrots, sliced diagonally
2-3 teaspoons sesame seeds (optional, I usually skip these)
1/4 cup oil, divided
2 cloves garlic, minced 
1/4 cup water

Prepare Cooking Sauce
Stir together 3/4 cup water, 4 teaspoons cornstarch, 2 teaspoons soy sauce, 1/2 teaspoon ground ginger, and 2 tablespoons cooking sherry. Set aside. 

Cut the beef with the grain into 1 1/2 inch wide strips; then cut each strip across the grain into 1/2 inch wide slanting strips. Place in bowl with soy sauce and garlic.  Let marinade for at least 30 minutes. 

Meanwhile separate Bok Choy leaves from stems.  Wash both thoroughly. Slice stems diagonally into 1/4 inch pieces. Set stems and leaves aside  separately .

Place wok over medium heat. When wok is hot, add sesame seeds and stir until golden (about 2 minutes); remove from wok and set aside.  Increase heat to high. Add 2 tablespoons oil to wok; when oil is hot add Bok Choy stems and carrots. Stir fry for 2 minutes; add water, cover, and cook for 2 minutes; add Bok Choy leaves, cover, and steam for 2 more minutes until leaves and stems are tender to bite. Remove from wok and set aside. 

Pour remaking 2 tablespoons oil into wok. When oil is hot, add meat; stir fry until browned, about 3-5 minutes. Return Bok Choy to wok. Stir cooking sauce and add to wok, then add sesame seeds. Cook, stirring until sauce thickens.  Serve with rice.