Place tofu in a bowl and add soy sauce. Toss well and set aside to marinate for 10-15 minutes.
In a blender or mixer add tamarind paste, peanuts, garlic, soy sauce, brown sugar, red chillies, salt and water. Grind to a smooth and creamy sauce. Set aside.
Bring a large pot of water to boil and add the rice noodles. Turn off the heat and let the noodles soak until edible but still firm and slightly crunchy. Drain and rinse in cold water.
Heat a wok or pan and add 1 tbsp oil. Add the tofu cubes and fry until lightly browned. Set aside.
In the same wok/pan, add ½ tbsp oil and add the carrot, beans and capsicum, Toss for 1-2 minutes and set aside.
In the same wok/pan, add 2-3 tbsp oil and add the noddles. Stir-fry the noodles for 1 minute. Then add 3/4th of the peanut sauce and stir-fry for 1-2 minutes.
Add tofu, bean sprouts, vegetables, basil and remaining sauce. Adjust the salt if necessary. Stir-fry until noodles are soft. Garnish with peanuts and green onions.