Grilled Sweet Potato and Walnut Seitan Sandwich

1. In a large zip-top bag, combine vegetable oil, five spice, nutmeg, salt, and pepper, and squeeze to combine. Place sweet potatoes in the bag and massage in the spices. Allow flavors to seep in for at least 30 minutes, massaging the bag every 10 minutes or so. Preheat oven to 350 degrees F. Toast walnuts for 8 minutes or until golden, mixing halfway through. Set aside to cool.
2. In a small saucepan, combine the cranberries, water, and red pepper flakes. Bring to a boil over high heat. Reduce heat to medium-high and cook for 15 minutes or until most (but not all) of the liquid is absorbed. Remove cranberries to a cutting board with a slotted spoon, reserving the liquid. In a medium bowl, toss the walnuts with the gluten flour, rosemary, and thyme.
3. Combine the soy sauce and enough of the reserved cooking liquid from the cranberries to make 1/2 cup (if there's not enough liquid from the cranberries to make 1/2 cup, add enough fresh water). Pour liquid mixture over the walnut mixture, and knead vigorously (it may help to use your fists to grind the walnuts into the flour). Continue kneading until a reasonably smooth dough is formed (the dough is mostly walnuts, and some of them may refuse to join the party).
4. Pour the mixture onto a 24x12” sheet of aluminum foil, and press into a large patty (about 1/2-1" thick by about 8" across). Fold over the long sides of the foil, then lightly crimp in the shorter edges. Place the package in a steamer, and steam for 45 minutes. Remove from steamer, and allow to cool completely before removing from foil. Meanwhile, roughly chop the cranberries, and add to a small bowl. Stir in the mustard and set aside.
5. Preheat a grill sprayed with nonstick spray to medium-high heat. Remove sweet potatoes from zip-top bag, and shake off excess marinade into the bag. Grill potatoes with the lid closed for 5 minutes without moving. Twist the potatoes 45°, then cook for 5 more minutes. Meanwhile, baste the potatoes with remaining marinade and close the lid. Flip the potatoes, cook for 5 more minutes with the lid closed.
6. While the potatoes cook, slice the walnut patty along its median, then 3 more times perpendicular to the first cut to give you 8 pieces. Cut them open to give you 2 halves. Turn off 1/2 the grill, and line it with a sheet of aluminum foil. Transfer all potatoes to the foil, and then arrange the walnut patty on the lit side of grill (some walnuts will undoubtedly fall off). Set a timer for 2 minutes and close the lid. Spray the cut side of the bread with cooking spray, position it next to the seitan, and cook for a final 2 minutes. Remove everything from the grill.
7. Press down the middle of each side of the bread to form a cannel in each 1/2. Spread the cranberry mustard evenly over each 1/2. On the lower 1/2, layer the seitan, then the potatoes. Pack the fresh spinach into the top 1/2 of the loaf, then carefully use it to top the bottom of the sandwich. Cut sandwich into 4 individual servings.
This recipe was really a lot more complicated to write than it was to make. There's a fair amount of down time, so you'll have time to clean up along the way.
Source of recipe: I wanted to play around with a new kind of sandwich. Slightly reminiscent of Thanksgiving, slightly awesome.