Clean the Chinese cabbage and carrots and cut them into thin strips. Make a Vinaigrette with 2 tbsp lemon juice, 2 tbsp dark sweet soy sauce and 2 tbsp olive oil. Cut the tofu into small squares and let it marinate for 30 minutes in 2 tbsp dark sweet soy sauce. Then fry them in the wok in olive oil. Remove the tofu from the wok and keep warm. Add the Chinese cabbage and carrots to the wok and cook for 1 minute. Add the bean sprouts, and cook for another 1 minute. Add the dressing to the vegetable mixture and divide between 4 plates. Garnish with the tofu.