Dinosaur kale - also known as Tuscan kale, Lacinato kale, black kale, or cavolo nero - is a very hearty cooking green with dark, dark green leaves and lots of earthy, nutty flavor. The leaves are so hearty that even when well cooked they retain a wonderful firm texture.
Look for the biggest bunches with the widest leaves you can find. Look at the leaves carefully, you want very dark blue-green leaves with no brown or wilted bits.
Store dino kale loosely wrapped in plastic in the fridge. When ready to use, be sure to rinse the leaves well.
Dino kale is particularly well suited to braising in a bit of broth. Or, simply blanch it in boiling water, then sauté it in olive oil with garlic and a chile or two, if you like. A sprinkle of salt and a squirt of lemon are nice, too.