Very thinly slice flank steak against the grain (it should be partially frozen to make this easier), and add it to a medium bowl. Add the water, cornstarch, vegetable oil, Shaoxing wine, baking soda, and salt. Mix well, and marinate for 30 minutes.
Meanwhile, bring a medium pot of water to a boil. Add the beef, and blanch for 45 seconds to 1 minute, just until it turns mostly opaque (it’s ok if it’s still a little pale pink in spots). Drain well and transfer the beef to a mixing bowl.
Add the garlic, chili, sugar, sesame seeds, and Sichuan chili flakes to the beef in little piles next to each other. Heat 2 tablespoons of vegetable oil in a small pan, and pour over the garlic, chili, and sesame seeds.
Add the vinegar, oyster sauce, light soy sauce, dark soy sauce, and cilantro. Toss and serve.