Fill a large saucepan or stockpot with the broth ingredients, cover with a lid and bring to the boil. Once boiling, reduce the heat to a very gentle simmer.
Place the dry seitan ingredients in a large mixing bowl and stir through to combine.
Add the wet ingredients to a jug and whisk with a fork to combine. Pour the liquid ingredients into the dry ingredient bowl and stir with a spoon until the mixture starts to come together. Use your hands to knead the mixture into a dough ball. Divide the dough into two equal pieces. Knead each piece for 3 minutes, then shape into a rectangle. Repeat with the second piece of dough.
Carefully lower the seitan into the broth. Partially cover with a lid and simmer for 45 minutes. Make sure that the water stays at a very gentle simmer. You should only see a bubble surface now and then. (If the water boils, the seitan will become very bubbly and holey on the inside).
After 45 minutes, turn the heat off, remove the lid and leave the seitan to rest in the broth for 15 minutes.
Place the seitan in a strainer to drain off the excess liquid. Once completely cool, transfer to an airtight container and store in the fridge, where it will keep for a week.
Before serving, pan fry the strips of seitan in a little olive oil. Add seasonings, to taste. For kebabs and curries, I like to flavour the home-made seitan with 1 tsp each of smoked paprika and ground cumin.