Start by pressing the tofu if you want to (I sometimes don't bother). If you don't have a tofu press, just sandwich it between two clean tea towels and place a few heavy books or pans on top, and leave for 30 minutes.
Cut the tofu into triangles or cubes. Heat the oil in a frying pan, and add the tofu. Cook over a medium heat for 5-10 minutes, turning regularly, until the tofu is golden brown and crispy all over.
Meanwhile, combine the sweet chilli sauce, soy sauce, chopped chilli, garlic and ginger in a bowl. Season with salt and pepper, and mix well.
Add the sauce to the crispy tofu, and allow to cook for another 5 minutes or so, stirring regularly, until the sauce has become thick and sticky.
Stir fry the vegetables in a separate pan, then serve with the sweet chilli tofu, topped with fresh coriander and some chopped spring onions.