Heat the miso and vegetable stock slowly (do not boil !) until the miso paste has dissolved completely. Clean, wash and cut the Chinese cabbage into strips. Clean, wash and slice spring onions diagonally.
Cut the tofu into slices. Cut slices diagonally in half. Heat oil in a pan. Fry the tofu on both sides until golden brown, remove. Add cabbage, spring onions and tofu to the stock and leave to stand for 5 minutes.
Season with rice wine vinegar, soy sauce and brown sugar. Arrange the soup in small bowls and garnish with alfalfa sprouts.