In a large saucepan cook the onion and garlic in hot oil until onion is tender but not brown. Add undrained tomatoes, and oregano or basil. Bring to a boil; reduce heat. Simmer, uncovered, about 3 minutes.
Meanwhile, place tofu in a food processor bowl or blender container. Cover and process or blend until smooth. Add to tomato mixture. Stir in cooked rice, spinach, half of the Swiss cheese, the salt, and pepper.
Grease 4 individual casseroles or one 2-quart rectangular baking dish. Spoon mixture into casseroles. Bake, uncovered, in a 350 degree F oven for 30 to 40 minutes or until heated through. Sprinkle with remaining cheese and sesame seed. Makes 4 servings.