Beijing Beef

This might honestly be my new favorite "at home" Chinese food recipe!!! (Thank you, Sarah!!!!!!!!!!) I've tried and tried over the years, to make something that tasted even remotely close to what I have when I eat out and this was pretty darn close. I did make a couple of minor changes and will reflect them below--I definitely trust my sister's judgment and thanks to her suggestions, it turned out perfectly! My husband not only had seconds, but made a point to mention that he thought it was the best "Chinese-style" dish I had ever made.

Beijing Beef

1 1/2 lbs flank steak (sliced thinly, against the grain)
6 tablespoons cornstarch (for dusting)
oil (for frying)

Marinade:
1 egg
1/2 teaspoon salt
3 tablespoons water
2 tablespoons cornstarch

Sauce:
10 tablespoons water
10 tablespoons sugar
7 tablespoons ketchup
3 tablespoons vinegar
1/2 teaspoon crush chili pepper (I substituted a little chili powder and red pepper flakes, b/c I didn't have chili pepper)
5 teaspoons cornstarch

Vegetables:
2 tablespoons garlic (minced)
1 medium red bell pepper (cut into chunks)
1 medium green bell pepper (cut into chunks)
1 medium vidalia onion (cut into chunks)

Directions:

In a bowl or resealable bag combine all marinade ingredients and mix well. Add beef slices and marinate for 15 minutes. While beef in marinating, mix all of the sauce ingredients together in a bowl and refrigerate. When the beef is done marinating coat the beef slices with 6 tablespoons of cornstarch. Remove any excess cornstarch and deep fry (either in a deep fryer or wok) beef slices in batches until floating or golden brown. Drain on paper towels. Add a couple tablespoons of oil to the wok and add minced garlic and stir fry for 10 seconds. Add red and green bell peppers and onions and stir fry for 2 minutes. Remove vegetables and set aside. Pour sauce into the wok and heat until boiling. Return veggies and beef to pan and mix with sauce mixture until well-coated.

Source: Delectable Dining