Start by boiling, steaming or microwaving your sweet potato. Once cooked, scoop out the flesh and mash in a bowl. Alternatively, you could use frozen cubes of sweet potato. Once boiled or steamed, place in a bowl and mash.
Meanwhile, place the spinach in a colander and pour boiling water over it until it shrinks. Rinse with cold water and then carefully squeeze the excess moisture out. Once it’s relatively dry, chop up finely and add to the bowl.
Add a whisked egg to the bowl, along with the breadcrumbs and combine the mixture with your hands.
Using a tablespoon, separate the mixture into small balls and roll in your hands.
Heat a little oil in a frying pan and place the rolled up balls. Flatten with the back of your tablespoon to create a burger shape.