nearly 40 years ago at the "Palace" * in Manchester. It served up mountains of rice and Ckicken (sic) with a choice of curry sauce. We worked our way up through Mild, Hot, Killer & Suicide then persuaded the boss to produce a "Special" just for us regulars. Then one night some tossers on the next table kept sending their sauce back as "not hot enough", eventually this bright red gloop came out which they took one taste of and refused to eat. Thoroughly pissed off, and pissed, by this time, I leant over picked up their bowl of sauce and drank it. How i did not end up in hospital I don't know, but it was worth it just to see the looks on their faces!
* The Plaza was a place of student legend at the time and the Palace was the competitor opened by (IIRC) on of the brothers at the Plaza when they had a falling out