1. Place the tofu, salt, and black pepper in the bowl of a food processor. Process until the texture resembles that of ricotta cheese, about 40 seconds. Add the scallions, and process until incorporated, 10 seconds more.

2. In a small bowl, whisk together the egg white and 1 teaspoon water; set aside.

3. Lay six gyoza wrappers on a clean work surface. Place a scant tablespoon of the tofu mixture in the center of each wrapper. Lightly brush the edges of wrappers with egg wash. Fold each ravioli in half, and press edges together to seal. Cover the sealed ravioli with plastic wrap, and repeat with remaining filling and gyoza wrappers.

4. Cut tomatoes lengthwise into quarters. Set a strainer over a small bowl. Hold a tomato quarter over strainer, and scoop out the seeds and juice; set flesh aside. Repeat with remaining tomatoes. Using a rubber spatula, press all juice through the strainer. Discard seeds and pulp. Dice reserved tomato flesh into 1/4-inch pieces.

5. Coat a medium nonstick saute pan with olive-oil cooking spray. Place over medium heat. Add garlic, cover, and let cook until translucent, stirring occasionally, about 3 minutes. Add diced tomatoes, strained tomato juice, and cayenne pepper. Season with salt and black pepper; cook 1 minute. Add balsamic vinegar, and cook for 30 seconds more. Cover, and remove from heat.

6. Bring a large stockpot of water to a boil. Add ravioli, and simmer until tender, about 4 minutes. Drain in a colander. Over medium heat, quickly reheat tomato sauce, about 30 seconds. Pour 1/4 cup tomato sauce onto each of four plates. Place 6 ravioli on each plate. Sprinkle with grated Parmesan; serve.