The scarcity of square frying pans with which to fry eggs means that if you're peckish for egg on toast, you'll either have to put up with an egg that's desperate to escape from its breaddy prison, or a bread:egg ratio that varies with each bite.
This is a solution to both problems!
Step 1: Toasting the Egg
Start by whisking a medium or large egg in something that's easy to pour from. In this case, less whisking tends to be better: If you whisk it much more than is necessary to break the yolk, your fried egg will turn into a miniature triangular omlette and expand dramatically (Although that's not such a tragedy!)
Heat up a sandwich toaster and pour a bout 1/2 tsp of oil into each of the two halves of the "mold". Once ready, pour the egg mixture into both parts in even quantities. It should cook in about half the time as a frying pan due to its increased surface area and being heated above and below.
At this stage, you can either remove the fried egg and use any remaining oil to part-fry / toast a slice of bread to make a simple (And rotationally symmetrical) egg on toast, or continue with the toastie.
Step 2: Converting It to a Toastie
The egg should be really easy to remove from the toastie maker, so put a slice of bread in the other half of the toastie maker, skewer the egg pieces with a fork, and transfer them to the other side, matching the pattern of the toaster's "cut" line. If you used the whole toaste maker for eggs, just transfer them to a plate temporarily.
Add whatever condiments or foodstuffs to the bread (Usually before moving the eggs over), top with another slice of bread, and press down! I opted for a not-quite-full-english-breakfast permutation.
Voila, your toastie is complete! Serve with whatever you feel like eating along with it, or treat it as a compact, on-the-go meal in itself!
I tried it with chips and baked squash