COOK RICE. SET THE TOFU on a slanted board or pan to drain, and prepare the vegetables. Chop the onion, carrots, celery, pepper, and zucchini into pieces about 1/2-inch square. Quarter mushrooms if they are small, and cut them into sixths or eighths if they are large. Cut the tofu into 1/2-inch cubes. Heat the olive oil and the butter and fry the onion over medium heat until it is lightly browned, about 5 minutes. Add the garlic, nutritional yeast, if using, cumin and salt. Stir until blended and cook for 1 minute. Add the carrots, celery, green pepper and 1/2 cup of the liquid, cover pan, and braise the vegetables until they begin to soften, about 5 minutes. Add the zucchini and mushrooms and cook 7 to 10 minutes. The vegetables should be nearly, but not completely, cooked. If the pan gets dry while they cook, add a little more liquid. Preheat oven to 350F. Combine the vegetables with rice and cheese. Season with salt and plenty of freshly ground black pepper. Gently mix in the tofu, and put mixture into lightly oiled casserole. Add a little more liquid to moisten. Cover with foil and bake 1/2 hour. Remove foil and bake 15 minutes. Garnish with fresh herbs.