The simple breakfast you can manage is more useful than the elaborate one you keep postponing.

The elaborate version is often a way of not starting. A plan needing shopping, time and energy you rarely have gives you something to intend rather than something to do, and intending feels productive while you go hungry. The modest version has one advantage that outweighs the rest, which is that it actually happens. Repetition beats ambition in anything you need every day.

Decide on the plainest breakfast you would genuinely eat and keep it stocked. Let the ambitious one be an occasional pleasure instead of a standing failure.