Bring a large pot of water to a boil. Cook manicotti shells until about half done, about 5 to 7 minutes. Drain, rinse and drain again.
While the shells are cooking, place the tofu, water, ume plum vinegar, parsley and shoyu in a blender. Blend until creamy. Stuff each manicotti shell with spoonfuls of tofu cream until each shell is full. Place in a baking dish and preheat the oven to 400°.
To prepare the sauce, heat oil in a medium skillet or saucepan and sauté the garlic for 1 minute. Add the onions and mushrooms, sauté 2 minutes. Add the zucchini, peppers and summer squash. Stir in the spaghetti sauce, water and basil. Cover and simmer for 10 minutes.
Pour the sauce over the stuffed manicotti, cover the baking dish and bake for 35 to 40 minutes until the shells are tender.
The manicotti shells can be parboiled for 3 to 5 minutes, rinsed and then stuffed. This will reduce the cooking time by about 15 minutes.
Yields 14 manicotti, 2 per pieces person
Per serving - 362 calories, 14 g fat (33% calories from fat), 23 g protein, 38 g carbohydrate, 4 g fiber, 0 mg cholesterol, 586 mg sodium