Stir-Fried Chopped Choy Sum

Name: Stir-Fried Chopped Choy Sum (Bo Bo Cai Xin 鉢鉢菜心)
Cuisine: Chinese
Ingredients: 1–2 tbsp chilli oil (optional); 1 tsp finely chopped garlic; 1 tsp finely chopped ginger; ½ tsp sesame oil; Salt; 1½ tbsp cooking oil, plus more for blanching and for seasoning the wok; 375 g choy sum; 1 tbsp finely chopped fresh red chilli