Preheat oven to 200 degrees celsius (fan-forced). Lightly grease 2 non-stick baking trays and set aside.
Peel and cut the sweet potato into 4cm chunks. Boil in a saucepan until tender. Drain well, place into a bowl and mash.
Add the strained zucchini (see notes) and the grated cheddar cheese. Mix until well combined.
Take tablespoon-sized spoons of mixture and shape to resemble a 'nugget'.
Press into the panko crumbs to coat and place onto the prepared trays.
Lightly spray with cooking oil and bake for 20 minutes. Turn and bake for a further 20 minutes or until slightly crunchy on the outside (the nuggets will be soft on the inside).
Serve with sauce or chutney (optional).
Store in the fridge for up to 3 days or freeze in an airtight container for up to 2 months.