Jiang Feng stayed in the kitchen of Jubao Building until dinner time.
All afternoon, he taught Sun Jikai how to thicken the sauce for the Eight Treasures Chestnut Fragrant Pigeon just as he had taught Ji Xia to make stuffed orange with crab. He had no special teaching methods; all he could do was demonstrate over and over again, explain as best he could, and then let Sun Jikai try his hand at it.
Whether Sun Jikai had any epiphanies, Jiang Feng had no idea, but he certainly felt the urge to hammer Sun Jikai's skull.
Through this teaching exercise, he found the same feeling as when he used to help the sisters Jiang Junlian and Jiang Junqing with their homework.
It was definitely Sun Jikai's lack of understanding, not any problem with his teaching ability.