Ginger Beef with Peppers and Bok Choy

1 lb (450 g) flank steak cut to 1/2-inch thick strips
1/3 cup cornstarch

Marinade
1 egg, beaten
1 tablespoon ginger, finely grated
1 tablespoon peanut oil (or vegetable oil)
1/2 teaspoon salt

Sauce
1/3 cup broth (beef, chicken, or vegetable)
3 tablespoons Shaoxing wine
3 tablespoons soy sauce
2 tablespoons Chinkiang vinegar
3 tablespoons sugar
2 teaspoons cumin powder
1 teaspoon red chili pepper flakes
1 tablespoon cornstarch

Beef and stir-fry
1/3 cup peanut oil
3 green onions, chopped
2 cloves garlic, thinly sliced
1 thumb ginger, sliced
1 bell pepper, sliced
2 baby bok choy, quartered

Beat the egg in a medium-sized bowl. Add the sliced beef, vegetable oil, and salt. Mix well and let marinate for 15 to 20 minutes while preparing the other ingredients.

Combine everything for the sauce in a big bowl and mix well.

When you’re ready to cook, add the cornstarch. Stir to coat the beef, until it forms an uneven coating with a little dry cornstarch left unattached.

Heat the oil in a large nonstick skillet (or a cast iron paover medium-high heat until hot. Add the beef and spread it into a single layer in the skillet. Separate the beef pieces with a pair of tongs or chopsticks.

Cook without touching the beef for 2 to 3 minutes, or until the bottom turns golden. Flip to brown the other side, 1 to 2 minutes. Transfer the beef to a big plate and remove the pan from the stove. Let cool for 2 to 3 minutes.

Place the pan back onto the stove and turn to medium heat. You should still have 1 to 2 tablespoons of oil in the pan. If not, add more.

Add the green onion, ginger, and garlic. Stir a few times to release the fragrance.
Add the bell pepper and baby bok choy. Stir and cook for 1 minute.

Stir the sauce again to dissolve the cornstarch completely. Pour into the pan. Stir and cook until it thickens a bit.
Add back the beef pieces. Stir to coat the beef with sauce.

Transfer everything to a plate immediately and garnish with roasted sesame seeds, if using.

Serve hot over steamed rice as a main dish.