Parsnips are a root vegetable similar to carrots, and they have a sweet, nutty flavor. They are off-white to pale yellow and are high in vitamin C. Parsnips can be cooked in various ways to release their tender, gentle sweetness and are often added in stews.arsnips are a root vegetable similar to carrots, and they have a sweet, nutty flavor. They are off-white to pale yellow and are high in vitamin C. Parsnips can be cooked in various ways to release their tender, gentle sweetness and are often added in stews.