Red onions, also known as 'purple onions', are a white and bulbous-shaped vegetable with a hint of purplish-red color on its inner and outer layers. These onions are sealed within a thin, paper-like skin which is discarded before being consumed. Red onions are a much-loved ground vegetable, especially in Indian-style cooking, where it is an essential ingredient. Red onions also go well with steak, salads, and sandwiches.