First, prepare the sauce mixture. Combine the sweet bean sauce, spicy bean sauce, rice vinegar, Shaoxing wine, dark soy sauce, and water.
Have all your ingredients ready before you start cooking. Preheat your wok over medium-high heat until it’s lightly smoking, and add 2 tablespoons of oil. Then immediately add the beaten eggs. Scramble them until they’re just done (they should still be a little runny), and quickly remove from the wok.
Add the remaining tablespoon of oil to the wok (still over medium-high heat), along with the tomato, chili (if using), garlic, and zucchini. Cook for a few minutes until the tomatoes are softened and the zucchini is tender.
Add the eggs back to the wok, along with the prepared sauce mixture. Stir, cover, and reduce the heat to medium. Simmer over medium heat for 3-5 mins. Add salt to taste and stir in the sesame oil.
Serve this mixture over your cooked noodles (alternatively, you can serve it over rice). Garnish with chopped scallion.