In the meantime, heat 2 tablespoons oil in a large skillet over medium heat. Add bay leaves and let sizzle for about 1 minute to flavor the oil. Stir in celery and onions. Reduce heat to low and cook, stirring occasionally, until the vegetables are soft, about 35 minutes; do not let them brown. Add capers and tomatoes, increase heat to medium and cook, stirring occasionally, just until the tomatoes start to break down, about 5 minutes. Stir in olives; thentransfer everything to a large bowl.