Seeni Sambol is a popular Sri Lankan caramelized onion relish, known for its sweet, spicy, and slightly sour flavor profile. It's a versatile condiment used in various dishes and enjoyed with rice, string hoppers, bread, and even in buns and sandwiches. The sweetness comes from the slow caramelization of onions, while other ingredients like tamarind, chili, and spices contribute to the complex taste.