Boil the egg and cool (this step can be done up to 2 days before).
Mash the egg with the avocado and spread evenly over one slice of bread.
Lay the other slice on top and cut in half.
(If giving to baby or young toddler, cut the crusts off the bread and cut into fingers).
Notes
Estimated costs: Australia $0.94UK £0.47pAmerica - I am yet to calculate the estimated ingredients costs to make this recipe in the US. If you would find it useful please let me know and I'll get calculating :)