Onion calcots are a type of green onion that is popular in Catalan cuisine. These onions are typically harvested young, before the bulb fully forms, resulting in a long, slender stalk with a small white bulb at the end. They have a mild, sweet flavor with a hint of onion sharpness. Onion calcots are often grilled or roasted whole, which caramelizes the sugars in the stalk and bulb, creating a deliciously smoky and tender dish. They are typically served with a romesco sauce for dipping and are a popular dish for outdoor gatherings and celebrations in Catalonia.