Tai Tung's Tomato Beef

http://chinesefood.about.com/od/beefdishes/r/beeftomatoes.htm

Tai Tung in Seattle is a Notis family tradition and Tomato Beef is one of our absolute favorite recipes. It looks deceptively simple, but I've played with online recipes a lot and this is the closest I can get to their wonderful dish.

• 3/4 pound beef
• Marinade:
• 1 tablespoon dark soy sauce
• 2 teaspoons water
• 1/2 teaspoon sugar
• 1 teaspoon salt
• Pepper to taste
• Cornstarch to lightly coat beef
• Other:
• 4 medium tomatoes
• 1 onion, thinly sliced
• Sauce:
• 1 Tbs tomato paste
• 2 teaspoons soy sauce
• 1 teaspoon sugar
• 1 to 2 tablespoons oyster sauce, as desired
• 1/3 cup water

Cut the beef across the grain into thin slices approximately 1 1/2 inches long. Place the beef in a bowl, add the marinade ingredients and mix in with chopsticks, adding the cornstarch last. If you like, you can also add a bit of baking soda to tenderize the beef. Marinate for 15 minutes.

While the beef is marinating, slice the tomatoes into six equal pieces.
Mix together the sauce ingredients and set aside.

Heat wok and add oil. When oil is ready, add the beef. Stir-fry until it changes color, turning the meat over once. Remove from the wok and set aside. Clean out the wok and add more oil. Saute the onions, and add the tomatoes. Add the sauce. Cover and bring to a boil. Return the beef to the wok and mix together. Serve hot over rice.