Fix this now, lecture me later

Something has split, burnt, or oversalted, and people are sitting down soon.

Something has gone wrong and dinner is soon. Tell me in two sentences what probably happened, then whether it can be saved: yes, partly, or no. Give one fix, the one most likely to work, as numbered steps I can start now. Then a plan B if it fails. One line at the end on the cause.

What I was making and what went wrong:
Time left:

When it goes wrong. It split, sank, or tastes flat. Work out the cause and the fix while dinner is still rescuable.