Beef and Chinese Broccoli Chow Fun

1. 1
   In a large saucepan, whisk together the soy sauce, black vinegar, sesame oil, pepper, and 1/4 cup water and bring to a boil. Reduce the heat to low.
2. 2
   Place the cornstarch in a small bowl and slowly whisk in 1 tablespoon cold water until smooth. Don’t use warm or hot water, as it will cause the cornstarch to seize up into small lumps that won’t dissolve no matter how hard you whisk. Slowly add it to the soy mixture on the stove, whisking all the while.
3. 3
   Bring the heat back up to medium-high and whisk until the mixture thickens, 1 to 2 minutes. It should be shiny and coat the back of a spoon. Remove the sauce from the heat and pour it into a bowl or container and refrigerate until cool. The sauce will keep in an airtight container in the refrigerator for up to 2 months.

Make the Chow Fun:

1. 1
   Place the beef in a medium bowl. Measure out about half the Fun Sauce (don’t use it warm or it will start to cook the beef) and add it to the beef along with the pepper, mixing to coat. (Keep the remaining Fun Sauce in an airtight container in the refrigerator.) Cover the bowl with plastic wrap and marinate in the refrigerator for at least a few hours or up to overnight. If you do this before you start your day, you’ll be ready to go by dinnertime.
2. 2
   In a wok or a large, heavy, flat-bottomed skillet, heat 2 tablespoons of the vegetable oil over high heat until the oil starts to shimmer, about 1 minute. Add the gai lan, broccoli, or rapini and the onions and use a wooden spoon or spatula to stir continuously for 3 minutes. Add about 3 tablespoons water to the hot wok and stir for another 2 to 3 minutes. The water will turn to steam as it hits the hot wok and continue to cook the vegetables. Turn off the heat and transfer the vegetables to a plate or large bowl. Set aside.
3. 3
   Wipe out the wok with a paper towel. Heat the wok over high heat for 30 seconds. Add 2 tablespoons of the vegetable oil and coat the wok again. Remove the beef from the refrigerator, drain any sauce into a bowl, and set the sauce aside. Add the beef to the wok, stirring immediately and continuously, and stir-fry for 2 minutes. Turn off the heat and transfer the meat to the same plate/bowl as the vegetables.
4. 4
   Wipe out the wok again with another paper towel and heat over high heat for 30 seconds. Add the remaining 2 tablespoons vegetable oil and coat the bottom of the wok. Add the rice noodles and stir to coat with oil. Add the scallions, ginger, garlic, and 2 tablespoons water and cook for 1 minute. Add the beef and vegetables and toss for 1 minute. Add the remaining Fun Sauce from the refrigerator along with the drained sauce from the beef and stir for 2 minutes. Shut off the heat, stir one final time, and divide among four bowls. Serve immediately.