Caramelized Onion and Blue Cheese Sourdough Bread

1. In a large mixing bowl, combine the sourdough starter, warm water, and sugar. Stir until the sugar is dissolved. 2. Add the flour and salt to the mixture and mix until a rough dough forms. Cover and let it rest for 30 minutes. 3. Meanwhile, heat olive oil in a skillet over medium heat. Add sliced onions and cook until they are caramelized, about 15-20 minutes, stirring occasionally. Let cool slightly. 4. After the dough has rested, add the caramelized onions, blue cheese, thyme, and black pepper to the dough. Fold until well incorporated. 5. Cover the dough with a damp cloth and let it rise in a warm place for about 4-5 hours or until it has doubled in size. 6. Preheat your oven to 450°F (232°C). Place a Dutch oven (with lid) inside the oven to heat up. 7. Once the dough has risen, transfer it to a floured surface and shape it into a round loaf. Place it on parchment paper. 8. Carefully remove the hot Dutch oven from the oven, lift the parchment with the dough and place it into the pot. Cover with the lid and bake for 30 minutes. 9. After 30 minutes, remove the lid and bake for an additional 15-20 minutes or until the bread is golden brown. 10. Remove the bread from the Dutch oven and let it cool on a wire rack before slicing.