As soon as Zang Liang finished speaking, Qin Huai moved.
Actually, Qin Huai didn't know when the best time was either, but as Zang Liang said, it's about feeling. The timing of thickening depends on the chef's intuition; if you feel that it's the right moment, then that's the best moment.
When Zang Liang was saying the last few words, Qin Huai couldn't hear his voice anymore.
He was staring into the pot, watching as the shiny Crab Yellow Sauce gradually boiled due to the high heat. As a small bubble rose and then popped, the feeling came to him.
The feeling told Qin Huai, it was now—quickly, pour your starch water.
Every time Cao Guixiang cooked and needed to thicken, Qin Huai watched her pour the starch water attentively.
Qin Huai knew what Zang Liang meant by pouring.
Quick, flamboyant, and graceful.