Slice flank steak against the grain into wide strips for stir-fry.
In a medium-sized bowl, toss the meat with 2 teaspoons of soy sauce and the baking soda. Set aside.
In a second medium-sized bowl, whisk together the oyster sauce, 2 teaspoons soy sauce, sugar, rice vinegar, and garlic clove.
Bring a large pot of water to a boil. Add the rice noodles and cook according to the directions on the packaging. When done, remove noodles with a pair of tongs and drain in a colander. Toss with a tablespoon of oil so the noodles don't stick together.
Pour enough oil into a large work to just coat the bottom and turn heat to high. When just starting to smoke, add the broccoli. Stir-fry until broccoli turns bright green and becomes tender. Transfer broccoli to the large bowl and set aside.
Rinse off steak and pat dry. Set aside.
Pour in two tablespoons of oil into a wok or cast iron skillet, and turn heat to high. When just starting to smoke, crack in the eggs. Using a wooden spoon, scramble the eggs. When set, add the noodles and a tablespoon of fish sauce. Toss well to separate the strands, and then let them cook for a minute.
Drizzle on the sweet soy sauce, toss well, and then let cook undisturbed until the noodles start to brown, about one minute.
Add the broccoli and steak back to the pan undisturbed until the noodles start to brown, and the steak cooks to your desired doneness. About 2 - 4 minutes. Toss well.
When everything is warm, pour in sauce. Stir fry until everything is coated. Turn off the heat and serve immediately.