Process tofu, mushrooms, onion, garlic, tamari, tomato juice and paste, barbecue rub, liquid smoke, and paprika in the food processor until smooth. Add gluten and flour and process another 2-3 minutes, until it pulls away from the sides and gluten strings have formed.
Spread the mixture in the pan. If it’s too stiff to make an even layer, let it rest for 5-10 minutes and try again.
Slice the seitan in half lengthwise, then make 9 crosswise slices to form a total of 20 ribz.
Combine broth, wine, ketchup, vinegar, and pepper in the bowl. Pour over the ribz, then cover the pan tightly with foil.
Place the baking dish on the cookie sheet in the oven, and bake for 1 hour 15 minutes.
Turn off the heat, carefully remove the foil, and leave pan in the over for another hour.
Remove from the oven and let cool completely.*
To grill the ribz, preheat your grill to medium-hight heat and lightly oil.
Cook the ribz for about 3 minutes, until char marks are visible. Rotate 90 degrees and grill another 3 minutes.
Flip the ribz and you should see a nice crosshatch of grill marks. Repeat on the second side and your grilled ribz are ready to impress.