Place sweet potato above some boiling hot water in a steam and steam until tender. Remove and set aside.
Add the broccoli to the steam and steam for a couple of mins just to slightly soften.
Add this into the sweet potato, along with the cheddar and black pepper and roughly mash to combine all together. Set aside and allow to cool.
Preheat oven to 200c or 400f (gas mark 6)
Add the beaten egg and mix.
Form into equal sized patties, you can make these any size you choose, small for little hands or slightly bigger for adults.
Place on a greased baking tray and spray over the top with some olive oil. Bake in the oven till golden on both sides, approx 30-40mins (carefully flip over half way through cooking time)