Cut the tofu into medium sized cubes. Pour some oil into a frying pan (I use a non-stick wok and am pretty generous with the oil too). Add the tofu and then turn the heat up to high. Cook the tofu until it starts to get brown and then add some brewers yeast (again, I'm pretty heavy-handed with the stuff, so its up to you how much you like).
After a few minutes add some soy sauce (I just splash some on and like to get the tofu a medium bown in color). Cook until the soy sauce has more or less evaporated. Serve with rice, vegetables, black beans, baked potato and a salad.