Mix the egg with the milk. Heat a large frying pan with 1 tablespoon oil over medium heat. Cook the egg until 70% done, about 2-3 minutes. Set aside.
Heat the same frying pan with 1 tablespoon oil over high heat. Add the tomatoes, sugar and water. Bring to the boil, cover and simmer for 5-8 minutes or until the tomatoes are soft. Adjust the seasoning to taste with salt, sugar and tomato sauce.
Add the egg back into the pan; mix into the sauce. Transfer to a serving dish and garnish with cherry tomatoes and spring onion.