Ah, right -- Shrove Tuesday, yes? That's such a delightful tradition you guys in the UK have, with the pancakes! We don't seem to do that in the US.
Thinking about getting started with my income tax return -- I like to do this early and be done before spring and nice weather does begin to set in.
Actually, it (Shrove Tuesday) is an old (pre) Lenten tradition.
So, it would go back to pre-Reformation times, to Catholic times.
In fact, in southern Europe, or parts of Europe (and indeed, South America) with a Catholic tradition, - Venice, Croatia, southern Germany, Austria, Spain etc - you'll find (but, not in Covid times, for obvious reasons, alas) the often spectacular Carnival tradition, which leads into - or, immediately precedes - Lent.
However, as a child, I loved it, - Mother, ingredients to hand, her ancient - sort of battered - cookbook out, suitably dog-eared at the open pancake or crepe page, (I recall being instructed to read the recipe out to her, when I was around six or seven - I can see now that she thought that good practice re reading) and, then, the prepared batter "resting", and, later on, voilà, pancakes.