Preheat the oven to 400 degrees F. Make the broth: Combine the turmeric, ginger, cinnamon, saffron and 1/2 teaspoon pepper in a medium saucepan over medium heat; toast, stirring, 1 minute. Add 2 1/2 cups water, the vegetable juice and harissa. Bring to a simmer and cook until slightly reduced, about 15 minutes; remove from the heat.
Prepare the vegetables: Combine the squash, turnips, celery, onion and raisins in a bowl; season with salt. Add 1 cup of the broth and half each of the cilantro and parsley; stir. Set aside the remaining broth.
Tear off four 16-inch sheets of parchment paper. Make the packets (see photo gallery): Arrange about one-quarter of the vegetable mixture on one sheet of parchment along with some of the liquid from the bowl. Top with 2 shiitakes, 2 bell pepper halves, 2 lemon pieces and 1 tablespoon butter. Seal as directed. Repeat to make 3 more packets; divide between 2 baking sheets.
Transfer to the oven and bake until the parchment puffs and the vegetables are tender, 35 to 40 minutes. Let rest 5 minutes before opening.
Meanwhile, prepare the couscous as the label directs; fluff with a fork. Bring the remaining broth to a simmer; stir in the remaining cilantro and parsley. Carefully open the packets; add the couscous, drizzle with the broth and season with salt. Photograph by David Malosh