1. Preheat oven to 400°F. Cut 4 15-inch lengths of parchment paper, and fold each in half. Set aside.
2. Whisk together orange juice, oil, garlic, and pepper in large bowl. Add broccoli, carrots, parsnips, seitan, and cranberries, and toss to coat with juice mixture. Season with salt and pepper, if desired.
3. Open folded parchment sheets like a book, and arrange about 2 cups vegetables to one side of crease on each sheet. Fold parchment over food so edges meet, then crimp and seal edges with small overlapping diagonal folds (see “Classic French Fold,” below).
4. Transfer packets to large baking sheet, and bake 15 minutes. Let stand 2 minutes before serving. Sprinkle with cilantro.