Microwave the broccoli in a glass bowl covered with plastic wrap (holes poked for ventilation), about 1 to 2 minutes.
In a small bowl, whisk together the soy sauce, sesame oil, 1 teaspoon cornstarch and baking soda. Slice the beef against the grain into thin strips and add it to your marinade. Let it sit for at least 20 minutes, or as long as overnight in the refrigerator.
In a separate small bowl, stir together the stock, rice wine, oyster sauce and remaining 1 teaspoon cornstarch until the cornstarch is fully dissolved.
Heat a wok or large skillet on high heat and add the oil. When a wisp of white smoke appears, toss the marinated beef and garlic into the pan. Cook for about 1 minute, continually moving the beef so it browns on all sides but is still rare. Once the beef is seared, add the broccoli and cook for an additional minute. Stir in the sauce and keep it all moving. Don't be afraid to scrape any bits off the bottom of the pan before they start to burn. Once the sauce has turned into a nice thick glaze, about 1 minute, serve immediately.