Gets upset about half the food being starchy stuff (6)
I believe the answer is:
stodge
'starchy stuff' is the definition.
'stodge' can be an answer for 'stuff' (I have seen 'Heavy stuff' mean 'stodge' so perhaps 'stuff' could also mean 'stodge'). I am unsure of the 'starchy' bit.
'gets upset about half the food' is the wordplay.
'upset' indicates an anagram.
'about' means one lot of letters goes inside another.
'half the' indicates taking half.
'gets' anagrammed gives 'stge'.
'food' with half the letters taken is 'od'.
'stge' enclosing 'od' is 'STODGE'.
'being' acts as a link.
Can you help me to learn more?
(Other definitions for stodge that I've seen before include "'Heavy, starchy food (6)'" , "Steamed pudding" , "Heavy food (colloq.)" , "Dull work" , "Sticky stuff" .)