To make the sauce, mix tomato ketchup, corn flour, sugar and water together in a bowl. Set aside.

Cut the tomato into smaller wedges. Set aside.

Add salt, pepper and fish sauce to the eggs and beat together.

Heat up oil on high heat in wok or pot. Add eggs and stir fry quickly until evenly cooked and just tender.

Remove from heat just before eggs have set completely and transfer to a plate. Set aside.

Heat the wok/pot again add in the chopped tomatoes. Stir fry until most of the flesh in the tomatoes has cooked down. Reduce to low heat and add in the tomato sauce mixture prepared earlier. Stir around until the mixture has thickened slightly.

Add the eggs back to the wok/pot and stir fry until everything is mixed.

Serve hot.