The most common and most likely answer to this crossword clue is the 8 letter word SHIITAKE
I've seen this crossword clue in Financial Times
S
H
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T
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More clues leading to the result SHIITAKE
- Mushroom to eat: keep mum two as a starter
- Quiet ones eat mushrooms
- Mushroom soup starter with fish, eating one before the other
- Mushroom — I will have it dunked in milky drink!
- Quiet ones steal such mushrooms
- Sort of mushroom — member of Muslim group holds a thousand
- Mushroom mum and I swallow around lunchtime?
- Jerk gets IIT admission, Japanese love it
Buddy explains!

The straight part
We know that "mushrooms" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case mushrooms = shiitake.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does SHIITAKE mean?
SHIITAKE noun- A wide, brown variety of edible mushroom, Lentinula edodes.