In a mixing bowl, combine flour, cornstarch, egg, water, salt and pepper. Mix until the batter is smooth and all the lumps disappear.
Drain the tuna chunks and flake it using a fork or spoon.
Then in the mixing bowl add the carrot, squash, sweet potato, bell pepper, tuna chunks, garlic, onion and spring onions.
Mix the ingredients thoroughly until the veggies are well coated with the batter.
Heat cooking oil in a frying pan about an inch deep. When oil is hot enough, scoop the okoy mixture using a small laddle and pour in the frying pan and shape it like a patty.
Make 2 to 3 patties on each batch and avoid them sticking on each other. Fry the patties until golden brown on each sides, top and bottom.
Then transfer to a paper towel lined plate and serve with vinegar dipping sauce (see recipe below).