Rapini is sometimes also called broccoli rabe. Its from the same family as broccoli (brassicas). Rapini is much leafy-er than broccoli, with the skinniest of florets that are now starting to flower so you’ll see the pretty yellow dotting it. The flavor is very similar to broccoli, but with a slight herbal woodiness that reminds me of incenses.
You can use it the same ways as you would kale. Give it a rough chop, and sautee or roast.