Heavy filling food (6)
I believe the answer is:
stodge
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">heavy filling food</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for stodge that I've seen before include "Heavy and indigestible food" , "Sticky stuff" , "Heavy, often starchy, food" , "'Heavy, starchy food (6)'" , "Steamed pudding" .)