Bring 2 liters of water to a boil. Add in 1.5 tbsp of salt and a big drizzle of olive oil. Then blanch the vegetables that take a longer time to cook first (such as broccoli, cauliflower, carrots, shiitake mushroom...). Let them cook for a minute. Then add the ingredients that take less time to cook (such as snow peas, green beans, Bok Choy stems...). Continue cooking them for 20 seconds. Take all the vegetables out. Set it aside.
Get your wok ready. Add 2-3 tbsp of cooking oil. Toss in the minced ginger, minced garlic, and the vegetables that cook really fast (such as cabbage, lettuce, spinach...). Stir them over medium heat for about 20 seconds.
Introduce the blanched veggies back to the wok. Keep mixing. Although we used some salt while blanching, we don’t how much sodium that the vegetables actually get so you want to give it a taste and add salt to adjust the flavor. Stir to mix.
Turn off the heat. Toss in some black pepper to taste and pour in some cornstarch water. Mix until the cornstarch water is thicken and you are done.