Question

The Rabbi wrote here in a responsum about making tea on the Sabbath that cooking is not a physical phenomenon but an action from everyday life. Can the Rabbi expand on that? What does it mean that cooking is an everyday-life phenomenon? After all, usually in everyday life we wouldn’t refer to the essence that comes out of the tea leaves into the cup as something that is “being cooked.” Usually, cooking is when you intend it, and you get some benefit from it, etc. … right?