Make the Seitan: Whisk together the vital wheat gluten, nutritional yeast, and all the dry seasonings in a large bowl. In a small bowl, whisk together all the wet ingredients.
Combine the wet mixture in to the dry and mix with a spatula until combined. Knead the seitan for 2-3 minutes until combined and stretchy. Shape in to a short and fat log. Bring a pot of water to a boil. Place the seitan in a steamer basket and steam for 30 minutes.
Mince the red onion, jalapeño, garlic, and cilantro. Whisk together the rest of the marinade ingredients and add to a large tupperware container along with the minced vegetables.
When the seitan is done steaming, let cool at room temperature. Once cooled, thinly slice the seitan and place in the marinade. Refrigerate overnight.
The next day, remove the seitan from the marinade and place on a chopping board. Slice the seitan in to strips (see photo for reference).
Heat a large pan on medium-high heat and add 1-2 tbsps of olive oil. Add the seitan and cook until golden brown and slightly charred.
Add the marinade and lower the heat to medium. Cook until the marinade has been absorbed. While seitan is cooking in the marinade, prep the rest of the ingredients.
Combine diced tomatoes, minced red onion, minced garlic, chopped cilantro, the juice of 1 lime, and salt + pepper to taste.
Prep extra limes, extra cilantro, guacamole, and heat up tortillas.
Assemble tacos by adding a healthy portion of carne asada on each tortilla and top with pico & toppings of choice. Serve and enjoy!