Place the gluten free flour, nutritional yeast flakes, and the seasonings in a large mixing bowl, and stir them together. Mix the liquids in a small bowl. Pour the liquids into the dry ingredients, and mix them thoroughly. You will end up with a large, firm mass in the bowl.
Knead the mass directly in the mixing bowl for about a minute to make sure it is well blended. Longer kneading will change the texture, and you may want to experiment with this later. Form the mixture into one smooth log. Wrap the log in plastic wrap twisting both ends tightly. Then, wrap the log tightly in silver foil. Place on a dry baking sheet.
Bake the "pastrami" in a 325 degree oven for 1 1/2 hours. When done, unwrap the pastrami, transfer it to a cooling rack, and let it cool thoroughly. When completely cool, wrap the pastrami tightly in plastic wrap and chill in the fridge overnight or longer before eating. Slice into paper-thin rounds.
Serve and enjoy!