Roast your garlic: Throw your garlic in the oven wrapped in foil for about 35 minutes at 400 degrees. Let the garlic cool so it is easy to handle. Once the garlic is ready you can make the dough.
Preheat the oven to 350 degrees.
Mix together the sourdough discard, flour, salt, butter, rosemary and garlic to make the dough.
Place the dough between two pieces of parchment paper and roll it out. The crackers should be about 1/16” thick.
Lightly brush the crackers with oil and sprinkle flaky salt all over the crackers.
Using a pizza cutter, cut the crackers. I like to do 1 and 1/3 inch squares but you can choose whatever size you like.
Poke each cracker with a fork to help keep them from puffing up too much in the oven.
Bake the crackers for 20- 25 minutes or until they start to brown. Remove from the oven and let cool.
Store crackers at room temperature for 1 week.