Combine starter and oil in a non-metallic bowl. In a separate bowl, mix together flour, salt and baking soda.

Add dry ingredients to bowl with wet ingredients. Combine. If necessary, knead the dough a few times to incorporate the last bit of flour. Cover bowl with a plate or towel and let rest for six hours at room temperature. Store in the fridge after this if you won’t bake right away. The dough will keep in the refrigerator for about a week. Let it warm at room temperature for 15 minutes to half an hour to making rolling easier.

When you’re ready to bake, divide the dough into two halves on a generously floured surface.

Preheat oven to 350°F.

Roll the dough out about two millimeters thick. If necessary, sprinkle with flour between rollings to prevent dough from sticking to your work surface.

Transfer the dough to ungreased cookie sheets.

Cut into rectangles with a pizza cutter or a knife. Sprinkle with salt.

Bake for 6 to 8 minutes, turn trays and bake 6 to 8 minutes longer. Crackers are done when crispy and slightly browned. (My oven is a bit cool, so your crackers may bake faster.)

Transfer crackers to a rack to cool. Store in a glass jar. These also freeze well.