I think it is possible only when you encounter the sentence another time (probably while strengthening the skill): you try again with your answer, and if it's still considered wrong you click "Report a problem", check 'My answer should be accepted', and copy your answer in the "Explain it here" window.
While "spalić" is not wrong in the cooking context (but may sound just too literal, as if your dish burned to ashes), the usual verb for burning food is "przypalić" :) As for "może"... I'd go with "umie", he kinda has 'an ability' to burn even the water. Of course that's sarcastic, but still.
The last word should rather be neuter "Smutne!", because what you mean is rather "(It is) sad!".