Muesli plus oat milk.
Cheapest way is Trader Joe’s since they sell both relatively cheaply and their oat milk is pretty good. But their muesli is a bit lacking so I prefer Seitenbacher’s muesli (order direct from them). Can toss in some more dried fruits from TJ’s too.
It’s more filling and nutritious than just cornflakes.
The only certainty is that it is going to blow up a Chinese consulate somewhere somehow.