This topic has been touched upon many times here, but never, as far as I know, given the well-deserved dignity of its own thread. I do not expect this to be a long discussion. I am hoping for a concise and above all knowledgeable overview, complete with technical details of basic ingredient, methods of preparation etc. that may serve as the “knowledge bank” of the title, ready to be referred to as the authoritative guide to the subject.

I’d like to start with the possibly contentious aspect of serving temperature. Regardless of the type of bread used, I advocate warm toast, neither finger-burningly hot nor unappetisingly cold. In my experience hot toast melts both butter (OSAA) and topping, resulting in a concomitant lack of the crispness for which toast is rightly esteemed; the slice sags defeatedly in the hand, all substance and texture lost. Crispness is strengthened by the practice of twice-toasting, which I hope Mr. Thep may step up and explain, if he’s in a charitable mood.