In a small bowl stir together the white sugar, soy sauce, white wine and chicken stock. Set the sauce aside.
Pat the tofu dry with paper towels and cut into cubes. Season the cubes with salt and pepper. Sprinkle cornflour over them on all sides.
Heat a little more than 2cm of oil in a large deep frypan over medium-high heat. If you have a deep-fryer fill to the recommended level and heat the oil to 180 degrees C. When the oil is hot add the tofu and fry until golden brown on all sides. Turn occasionally. Remove from the oil with a slotted spoon and drain on paper towels.
In a separate frypan heat one tablespoon of oil over medium-high heat. Add the onions and green beans then cook and stir for 3 to 5 minutes. Season with salt and pepper. Stir in the tomatoes and cook until they begin to break apart; about 4 minutes. Add the bamboo shoots and stir to blend.
Stir the sauce into the frypan with the beans and bring to a boil. Cook for 5 minutes stirring occasionally. If the liquid starts to evaporate too much stir in up to 1 cup of chicken stock.
Mix together the remaining 2 tablespoons of cornflour and water until cornflour is dissolved. Stir this into the sauce in the frypan. Simmer stirring gently until the sauce clears and thickens.
Add the fried tofu and stir to coat with the sauce.