Marinade: Make the marinade by mixing together the sugar, salt, soy sauce and cornflour slurry. Mix in the minced pork, let marinate for 20 minutes.
Sauce: In a small bowl, mix together the tomato sauce, sugar and salt to make the sauce. Set aside.
Stirfry: Blanch the carrots in boiling water for 3 minutes. Add the celery and blanch for 1 minute. Drain well and put aside.
Heat a large frying pan with oil over high heat. Stir-fry the pork until cooked through; 4-5 minutes. Set aside.
In the same frying pan heat 1 tablespoon oil over high heat. Stir-fry the garlic until fragrant, 2-3 minutes. Add the onions with salt then cook until soft; 3-4 minutes.
Add carrots and celery, stir well. Add pork, tomatoes and water. Stir, cover and simmer for 2-3 minutes.