Drain the tofu and cut into cubes. Scald the tomatoes in hot water, rinse with cold water, remove the skins and cut into eighths. Rinse, trim and cut the leek and celery into wide pieces. Peel the shallots and garlic and finely chop. Rinse the mung bean sprouts in a colander with cold water and drain.
Heat the vegetable oil in a pan, add the tofu and saute. Add the shallots and garlic and cook briefly. Stir in the remaining vegetables, sprouts, yogurt and spices. Bring to a boil, cover and simmer for about 10 minutes over low heat. Meanwhile, grate the zest from the lemon and squeeze the juice. Stir the lemon zest into the curry and season with salt, pepper and lemon juice. Before serving, sprinkle with the parsley.