Make the corned beef broth by adding all the broth ingredients to a large pot. (Use a tea ball or spice pouch for the pickling spices.) Simmer the broth ingredients for 15 minutes then turn off the heat and set it aside. (You will use 1 cup in the dough and the other 7 cups to simmer the corned beef.)
Press a block (14 oz.) of tofu and crumble it into a food processor, then add 1 cup of the flavored broth, 1 tablespoon of ketchup, 1 teaspoon of salt, and 6 drops of food coloring and blend until it turns into a creamy thick liquid.
Pour the mixture into a glass bowl, then add 1 cup of vital wheat gluten and mix well until a thick dough forms.
Add another 1/2 cup of vital wheat gluten and knead it into the dough until all the wheat gluten has been absorbed and no longer feels wet. (You may have to add an additional 1-3 tablespoons of wheat gluten until the dough is firm enough to hold its shape firmly.)
Form the dough into a cylinder loaf shape like corned beef.
Place the seitan in a large pot and pour the remaining 7 cups of broth over your seitan loaf, add 2 tablespoons of oil and cover with a lid. Bring the broth to a boil over medium heat, then turn down the heat to low and simmer for 1 hour and 15 minutes, turning the roast over in the broth after 45 minutes.
If you want to eat it immediately, remove it from the broth and place it in a colander to allow the excess broth to drip out, then slice and serve. (You can use the remaining broth to boil cabbage and or potatoes too.)
To cook vegetables
Add 8 cups of your choice of vegetables (I like cabbage, potatoes, and carrots) to the remaining spiced broth. Add water until the vegetables are covered, then boil for 20-25 minutes until the potatoes are soft and cooked through. Serve with the seitan corned beef.
Notes
For the firmest most meat-like texture, store the loaf in the broth in the fridge overnight then simmer again for 15 minutes to heat it up.
For the firmest most meat-like texture, store the loaf in the broth in the fridge overnight then simmer again for 15 minutes to heat it up.
If you don't want mustard or coriander seeds sticking to your seitan, you can put those in a tea ball.
If you don't have a tea ball, you can wrap the spices in a piece of cheesecloth and then tie it up with a cotton string.