"But how can flour and water have any flavour?" Isn't that what the toppings are for, like sauce with pasta? (flour and water as PP said)
Families is right though, the point of pancakes tomorrow is to use up all the fat in the house before the fast starts. That said, presumably you do need much the same quantity of fat to fry them in as you would for normal pancakes and really, how many of us are actually starting a fast on Weds?
I love the way some Christian teachings/traditions stick and others don't. Queue outside the chip shop every Friday night, pancakes on Shrove Tuesday, Hot Cross buns all year round, fasting, giving up your riches and loving thy neighbour, not so much.