Pour boiling water over the tofu, cover if possible, and leave for 10 to 15 minutes. Chop the onion. Dice the potatoes and carrot into small pieces. Add the yeast extract to the stock or water and bring to the boil in a saucepan. Add the onions and potatoes, lower heat, and leave to simmer for 7-10 minutes. Add the carrots and cook for a further 4-5 minutes. While the vegetables are cooking put the 1/2 cup flour in a bowl and mix in salt and baking powder. Cut in the margarine, then pour in enough soy milk (about 2 tablespoons) to make a soft dough. Divide the dough into four balls. Put the soy sauce, water, and vinegar into a small bowl. Drain the tofu and squeeze it gently to extract excess liquid. Cut it into small dice. Put the dice into the bowl with the soy sauce mixture and stir it round; the liquid should be absorbed rapidly by the tofu. Spread the 2 tablespoons flour on a plate and turn the tofu cubes in it. Heat the oil in a skillet and stir-fry the tofu cubes until lightly browned. Add the tofu cubes to the vegetable mixture and turn into an oven dish. Flatten the dough balls and place them on top. Place in a 435F (220C) Gas Mark 7 oven for 15 minutes and serve immediately. Leah Leneman, "The Single Vegan"