Pierce sweet potato with a fork and microwave for approx 8 mins till slightly soft. Cut in half, scoop out flesh and roughly mash in a large bowl (If you prefer, you can steam in a steamer until fork tender)
Preheat oven to 200c or 400f (gas mark 6)
While the sweet potato cools down, Add avocado oil to a frying pan over a medium heat. Saute the onion to soften, stir in the red pepper and zucchini and just fry for couple more mins.
Add this to the sweet potato, along with the tuna, pepper, eggs and fresh chopped parsley.
Combine all ingredients together.
Line a baking tray with some parchment paper, form the mixture into equal sized patties, place on tray and bake in the oven for approx 30-40 mins till edges are golden and patties are firm.
Serve with your choice of sides and a dipping sauce of your choice.