Step 1: In a medium bowl, combine your unfed sourdough discard, olive oil, and salt. Whisk them together until well incorporated.
Step 2: Gradually add the all-purpose flour, mixing with a spatula or your hands until a shaggy dough forms. Continue to mix until no dry streaks of flour remain.
Step 3: Turn the dough out onto a lightly floured surface and knead gently for just 1-2 minutes until it forms a cohesive ball. It should be soft and pliable. If very sticky, add a tiny bit more flour.
Step 4: Divide the dough into two or three equal portions. This makes rolling much more manageable.
Step 5: On a piece of parchment paper, roll out one portion of dough as thinly as possible (paper-thin, almost translucent). The thinner you roll, the crisper the crackers will be.
Step 6: Using a pizza cutter or a sharp knife, score the dough into desired cracker shapes (squares, rectangles, triangles). Do not cut all the way through yet. Brush lightly with a little extra olive oil and sprinkle generously with flaky sea salt or your chosen toppings.
Step 7: Preheat your oven to 350°F (175°C).
Step 8: Carefully slide the parchment paper with the scored dough onto a baking sheet. Bake for 15-25 minutes, or until the crackers are deeply golden brown and crispy. Keep a close eye on them, especially towards the end, and rotate the pan halfway through for even baking.
Step 9: Once baked, remove the crackers from the oven and let them cool completely on the baking sheet. As they cool, they will become even crisper. Once cool, break them apart along the scored lines and store in an airtight container.