Get your toast going.
In the meantime, start heating up the skillet (or sauce pan, or whatever) for your egg. I usually fry an egg over easy, because it is the quickest and surest way to a delicious runny egg, but you could poach, or soft-boil, and of course you could fry sunny-side up or over-medium or over-hard (what on earth). This is also good with scrambled eggs (we do this sometimes as a breakfast burrito, using a tortilla - corn and flour are both good- instead of toast) and hard-boiled eggs, but the runny egg is pretty tough to beat, as far as I'm concerned.
When your toast is toasted to your liking, spread with butter and Vegemite.
Mash your avocado with the sambal oelek, you can do it in a separate bowl, on the toast, or in the avocado skin. Add the avocado onto the toast.
Top with your egg and eat!