Prized subterranean fungus (7)
I believe the answer is:
truffle
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">prized subterranean fungus</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for truffle that I've seen before include "Underground delicacy" , "Soft chocolate; fungus" , "Rich-flavoured fungus that grows undergrond" , "Fretful for tasty underground fungus" , "fungal growth" .)