Add sourdough discard (or active starter), flour, olive oil, salt, oats and seeds to a mixing bowl and bring the ingredients together to form a pliable dough (see notes).
Divide the dough into two portions (this makes it easier to roll).
Place each ball onto a piece of parchment paper and flatten out with your hands into a rough rectangle.
Now roll out to a thin sheet of dough using a rolling pin. You want it around 1/16" or 1.5mm thick.The dough should not be sticky at all and easy to roll - however see notes below for some troubleshooting if your dough is sticky.
Use a sharp knife or cookie cutter to cut the seeded sourdough crackers into pieces.
Place each parchment paper with dough on top onto a baking sheet. This recipe will generally needs two baking trays.
Brush dough with olive oil and sprinkle with salt. You can also sprinkle with more seeds like sesame if you wish.
Bake at 350F/180C for around 30 minutes or until crackers are golden and crisp.
Let the crackers cool on a rack before breaking into individual pieces.
Notes
Notes on Discard - This recipe is based on a sourdough discard from a 100% hydration sourdough starter.Notes on Seeds - In the batch of crackers in these photographs I've used:
30g black sesame seeds
30g flax seeds
20g black chia seeds
10g cumin seeds
10g poppy seeds
Notes on Mixing Dough - This dough is easy to mix in a bowl with a dough scraper or your hands. I find it easiest to use a dough scraper until the dough has just come together. I then use my hands to knead the dough in the bowl until all the ingredients are combined.It's not a sticky dough - it should be soft and pliable.If you feel the seeds have absorbed some of the moisture or it's too dry, add a 10g of water at a time until the dough becomes pliable - but not sticky.Notes on Rolling Dough - The dough shouldn't be sticky and is easy to roll out using a rolling pin without it sticking. However, if you are working in a warmer climate or your dough is sticky for whatever reason, you can place the dough into the fridge before rolling it out. Alternatively, you can place the dough between two sheets of parchment paper to stop it sticking to the rolling pin.