Peel and cut the potatoes into chunks of a uniform size and soak in water to remove any bitterness.
Put in a ziplock bag or any other kind of microwaveable bag and put the potatoes in the microwave. Leave the bag unsealed and warm the potatoes – they should soften in about 4- 5 minutes.
Squeeze out any excess air and seal the bag. Crush the potatoes with a rolling pin whilst they are still warm.
When the potatoes are cool to the touch, add the sugar and margarine into the bag, close it up and rub the margarine into the sugar.
To finish crushing the potatoes, either roll over the bag with a rolling pin or mash with your fingers. Mash to whatever consistency you want.
Add the egg yolk. I wanted to save some for glazing, so I beat it first in a separate container. If you don't want a glaze, just add it straight to the bag.
If you are going to glaze your snacks, save about 2 - 3 teaspoons of egg yolk and mix with a little mirin.
Once the egg yolk has mixed in with the other ingredients in the bag, add the cream and mix well again.
To avoid dirtied hands, fill the cups by snipping off a corner of the vinyl bag and piping the mixture in.
Here, after piping in the mixture I flattened half of the snacks down with a knife and made half into ball shapes.
Coat with the glaze if you are using one and bake in an oven preheated to 180°C for 20 minujtes to finish.
Story Behind this Recipe
My eldest son picked some potatoes and brought them home. I created this recipe so that it only includes the crucial steps, so there is no need to sift ingredients and you won't have too much washing to do! For measuring I use a big plate and rest the bag on top of it, just tossing in the ingredients after I measure them. The margarine and sugar will melt from the residual heat from the potatoes, so they'll be easy to mix in. These taste just as good as more complicated sweet potato bites.
When heating the potatoes up in the microwave I used the setting for cooking root vegetables. Heat and keep checking on them until they soften. If you roll them into balls after piping they tend not to stick to your hands! Since they're small, feel free to freeze these and put them in your lunchbox for the next day.