The most common and most likely answer to this crossword clue is the 7 letter word HASHISH
I've seen this crossword clue in The Daily Telegraph
H
A
S
H
I
S
H
More clues leading to the result HASHISH
- Drug in dish is heroin
- Pot contains that man’s goulash, ultimately
- Key issue: no girl getting hot tea
- Mince is hot in pot
- Drug used when man’s between hospitals
- Dope, one tucking into hot kebab
- Man’s in mess with drug
- Grass residue is found in two hotels
- Obtains the man’s hospital drug
- Intoxicant gets him almost sent initially to hospital
Buddy explains!

The straight part
We know that "Grass" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case grass = hashish.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 HASHISH mean?
HASHISH noun- The leaves and tender parts of the Indian hemp plant (which are intoxicating), which are dried for either chewing or smoking.
- A cannabis extract.
- Marijuana generally.