I imagine this depends on what the food is. With spaghetti, you can add water or change water if you detect it on time. But what about grilled meat? Or a tomato sauce?
Before cooking a steak, you're supposed to let it sit out at room temperature. You're also supposed to salt it. What is the proper timing for these steps? How long do you let the steak come up to ...
Fleur de sel is the salt from the top of the pot when you heat salted water. But what makes it different from the rest of the salt in the pot?