Step 1

Add 1 tablespoon of oil into a medium-sized skillet and heat over medium heat until hot. Add the tomato and a pinch of salt. Chop and stir the tomatoes until the tomato pieces break down, 4 to 5 minutes. Pour in a small splash of water if the pan becomes too dry. Add the tomato paste. Keep stirring for 1 minute until the tomato paste is evenly mixed. Transfer to a bowl and set aside.

Step 2

Combine the soy sauce, Chinkiang vinegar, sesame oil and sugar in a large bowl. Stir to mix until the sugar has dissolved. Add the noodles and stir to combine.

Step 3

Add the white part of the green onion, garlic, chili flakes, sesame seeds, cumin powder and ground Sichuan peppercorn on top.

Step 4

Heat the oil in a small saucepan over medium heat until hot. Immediately pour the hot oil over the noodles, covering as much seasoning as possible. Then stir everything together to mix well while the oil is still hot.

Step 5

Add the tomato sauce and mix again (if using).

Step 6

Garnish with baby bok choy and cilantro. Serve immediately.