Caramelized Onion Ciabatta

Ingredients (16)

• Poolish (starter):
• 2 1/2 Cups (11.25 ounces) bread flour
• 1 1/2 Cups water, room temp
• 1/4 Teaspoon yeast
• Bread:
• Poolish starter from above
• 3 Cups (13.5 ounces) bread flour
• 1 3/4 Teaspoons salt
• 1 1/2 Teaspoons instant yeast
• 6 Tablespoons to 3/4 Cup water, lukewarm (I actually used 1 Cup)
• Onion filling:
• 2 onions, sliced
• 1/4 Cup olive oil
• 2 Tablespoons sugar
• 2 Tablespoons balsamic vinegar
• 3 Tablespoons fresh rosemary, minced