In a medium bowl, toss together the beef, baking soda, and 1/4 cup water, and allow it to marinate for 1 hour. The baking soda will help to tenderize the beef. Then “wash” the beef under running water for 5 minutes, using a light to moderate stream of water so it flows out, but the beef stays in the bowl. After the beef has been rinsed, pour out the water, and marinate the beef with two teaspoons of cornstarch. Set aside.
Heat 1 tablespoon of oil in your wok over high heat. Stir fry the bean sprouts for about 2 minutes, then add the Enoki mushrooms. Stir and mix everything well until the mushrooms have wilted. Turn off the heat, pick a large serving bowl with some depth, and spread the bean sprouts and Enoki mushrooms around the bottom of the bowl.
Now wash the wok. It’s important to start the next step with a clean wok!
Heat a ¼ cup of oil in the wok over medium heat. Cook the ginger slices until they start to turn light brown. Add the scallions and the Sichuan peppercorns. Cook for two minutes, making sure to avoid burning the spices. Now add the spicy bean sauce/paste, stir, and let the sauce cook in the oil for about 3-4 minutes. This will give the oil a bright red color. It’s important to control the heat––too low and the oil won't turn that vibrant red color; too high and you’ll burn everything!
Once the oil takes on a bright red color, add the stock and sugar. Turn up the heat to high, stirring, and let the liquid come to a boil. Immediately add the beef, and stir slowly to separate the pieces, still using high heat. Quickly turn off the heat once all the beef pieces turn opaque. (You don’t have to cook the beef completely through––a hint of pink in the middle equals tender beef.) Now, pour everything over the vegetables in the bottom of your serving bowl.
Top it with the minced garlic, chili flakes, and chopped cilantro. In a small saucepan, heat the last 3 tablespoons of oil until shimmering. Pour the heated oil over the garlic and chili in a very thin stream––you should get a good sizzle. Finally, add a dash of ground Sichuan peppercorns over the top to finish this dish off on an even higher note. To serve, mix everything together and enjoy this dish of spicy, numbing, meaty awesomeness with plenty of white rice.