Step 1

Dissolve the starter in the water.

Step 2

Add the salt to the flour.

Step 3

Stir the liquid mix into the flour then gradually bring together, using a rubber spatula or spoon, into a rough dough that leaves the sides of the bowl clean.

Step 4

Cover the bowl with cling film and leave overnight or 12-16 hours.

Step 5

Heat the oven to 180C/350F/Gas 4

Step 6

Put the chopped onion in an ovenproof dish, and add salt, pepper, sage and olive oil. Stir to combine then cook until onion is soft and starting to brown (25-30 min). Watch it doesn't burn. Cool and leave in the fridge overnight.

Step 7

Heat a dry frying pan to moderately high and put in the dry bulgar wheat. Stir around until nicely toasted, without burning (5-10 min). Put in a heatproof bowl at least 4 times the volume of the bulgar.

Step 8

Pour over boiling water from a kettle: be careful if the bulgar is hot as it will splutter! Add enough water so it's twice the depth of the bulgar. Stir and leave to soak. If all the water has been absorbed and the bulgar hasn't plumped up, add a little more.

Step 9

Add the flaxseeds to the soaked bulgar, cover and leave in the fridge overnight.

Step 10

Tip the bulgar and flaxseeds into a sieve to remove any excess liquid. Set aside.

Step 11

Scrape the dough out of its bowl onto a well-floured worktop and flatten out.

Step 12

Spread half the bulgar/flaxseed mix and half the cooked onions over the dough. Fold over the sides of the dough to cover the mix and flatten the dough again.

Step 13

Spread the rest of the bulgar, flaxseeds and onions over the dough, fold over the sides again and continue folding until the filling is incorporated throughout. You might need to flour the dough and your work surface several times to stop it sticking.

Step 14

Shape your loaf to the proving vessel, cover with cling film and leave to rest 10 min.

Step 15

After 10 min place the dough into lined, floured proving basket or tea towel-lined bowl, cover with cling film and leave for 90 min.

Step 16

After 60 min preheat oven to 250C/500F/Gas 10 and put a cast iron pot with lid into the oven.

Step 17

After 90 mins, carefully flip the dough from the proving basket into the pots slash the top, replace the lid and put in the oven. Turn heat down to 220C/425F/Gas Bake for 30 min.

Step 18

After 30 min remove pot from the oven, take bread out and put bread directly on the oven shelf. Bake for 10-20 min until the bread is cooked through, turning down the oven if necessary to stop outside burning.

Step 19

Leave on a wire rack to cool.