Add the vital wheat gluten, lentils, nutritional yeast, garlic powder, smoked paprika, chili powder and black pepper to a food processor and blend until combined.
Whisk together the tomato paste, soy sauce, beefless bouillon, water and liquid smoke in a separate bowl.
Add the wet ingredients to the food processor and pulse until just combined, making sure not to over process.
Dump the seitan onto a work surface, it should be crumbly. Knead by hand until it comes together, again careful not to overknead to avoid a chewy seitan.
Roll the seitan out as large as you can so that it will fit in your largest pot / dutch oven. You can also cut it into 2 and roll it out into 2 separate steaks. I rolled mine to about 1/2" thick. Let the steak rest for 10-15 minutes, then tightly wrap in foil. You can also wrap it in parchment paper first if you don't want the foil to touch your steak.
Bring some water in a large pot up to a boil, then add a steamer basket and then add in the wrapped seitan steak. Cover and steam for 25 minutes, flipping halfway through.
Let the seitan rest until it's room temperature. Then add it to a freezer bag or tupperware with the marinade and let it marinade for at least 1 hour, but overnight is best.
Heat up a grill and then grill the carne asada seitan steak on both sides to your desired doneness. Baste it with the marinade everytime you flip it. I cooked mine on both sides twice for about 3 minutes each time, so 12 minutes in total.
Once cooked, chop up into bite size pieces, and add it back to the bag / tupperware with the excess marinade to soak in more flavor and juice! Then serve as tacos, burritos, tortas, whatever you like!
ENJOY!