Add the prawns, ginger (peeled with a spoon is my favourite method!), garlic (peeled), egg whites, sugar, spring onions and light soy sauce to a food processor. I use a Nutribullet, as this is what I have, but if you don't have a food processor you could use a pestle and mortar, or even a plastic bag that you place the ingredients in and hit with a rolling pin!
Blitz for just a few seconds until you have a thick paste, ideal for spreading onto bread.
Then spread this blended mixture on to one side of each of your pieces of bread.
Press down into the sesame seeds, on a plate works well, spread side down, to ensure an even covering of sesame seeds.
Heat 2-3cm of vegetable oil in a wok, then carefully place one piece of your sesame prawn toast into the oil, starting with the bare side, for 1.5 - 2 minutes.
Flip and cook on the spread/sesame seed side for 1-1.5 minutes until golden brown.
Place on to a piece of kitchen towel to absorb some of the greasiness.
Cut (carefully!) into four triangles.
I always cook one piece at a time, just because this works space wise, and it means I can keep an eye on it to ensure that it doesn't burn, as it can turn VERY quickly.
Serve with a dip of your choice and enjoy.