But why is it called an egg banjo?
Once again you need to picture the scene...
You've fried your egg (for full effect, the consistency of the yolk should be runny), and laid it lovingly on a slice of bread. The type of bread (including bread rolls), and whether or not it is buttered, is of little importance: it's the consistency of the yolk that counts.
Having applied the necessary seasonings, you close your sandwich and take this gastronomic masterpiece in your hand. Then with no small amount of anticipation, you take your first bite.
If you have constructed your banjo with a sufficient degree of care and diligence, at this point the yolk will spew forth from the far edge of the sandwich and splatter its yellowness down your best pulling shirt.
Transferring the fruits of your labours into one hand, you hold it to the side, and with a futile strumming action attempt to wipe the spilt and rapidly-drying yolk from your shirt.