Bring 1 inch of water to boil in medium pot with steamer rack. Add squash and steam until very soft.
Transfer squash to food processor. Add rice milk, nutritional yeast, miso, garlic powder, salt and nutmeg and process until combined and smooth. Turn processor off, scrape down sides and pulse one last time to combine all ingredients. Set aside.
Preheat oven to 350°F. Lightly oil an 8x8-inch baking dish.
Cook macaroni according to directions on package. When nearly done, add peas and chard to cooking water with macaroni and remove from heat. Drain and return to pot. Pour squash mixture into pot and fold to evenly coat pasta and vegetables. Transfer to baking dish and spread evenly.
In small bowl, combine breadcrumbs with olive oil and mix until moist. Spread over casserole, sprinkle with paprika and bake 30 minutes, or until breadcrumbs are lightly toasted. Remove from oven and serve.
Reprinted with permission from Eat Clean Live Well © 2014 by Terry Walters, Sterling Epicure, an imprint of Sterling Publishing Co., Inc. Photography by Julie Bidwell