Tenderstem Broccoli is a cool season crop, closely related to cabbage, cauliflower, kale, and mustard. Broccoli is a high-quality vegetable for fresh use and is one of the more popular frozen vegetables. Tenderstem Broccoli is highly nutritious and has been deemed an anti-cancerous food. This vegetable is a good source of vitamin A ,calcium and riboflavin (or vitamin B2). The edible portion of the broccoli plant consists of the tender stem and the unopened flower buds.