I pulled out my seed starting flats and potting soil just a few days ago and sowed some 'Marathon' broccoli seeds. Now, just 3 days later they've germinated and I moved them under the grow lights. Marathon (from Johnny's) is a very cold tolerant type and is ideal for a fall planting (or winter if you're in a milder climate than me!). If you don't have a fall type, it's still worthwhile planting a regular broccoli from your local seedrack. If hard frost threatens early, you can always toss a row cover or a mini-hoop tunnel over the bed.
I also planted two types of Kale - Winterbor and Lacinato - both are hardy and delicious! Kale is a superfood, yet it's just not planted as much as it should be. Not only is it nutritious, but it's also very pretty in the garden, offering architectural interest well into winter (longer if planted in a cold frame, large cloche, mini-hoop tunnel or unheated greenhouse.
Lacinato (my seed pack is from Renee's Garden - love their website!) is also called Dinosaur Kale and it is one of the most elegant veggies you'll ever meet! The long, strap-like leaves are a deep blue-green and have a unique blistered texture. It grows about 2 1/2 to 3-feet tall and can be used in soups (bean and kale soup!), stews and many other dishes. It's also an open-pollinated type, so you can save the seeds for future crops.
I like to put kale in the food processor and turn it into confetti. Stick the bag in the freezer and then add handfuls of kale confetti to soups, stews, gratins, omelets, whatever! It's an easy (and cheap) way to get a nutritional burst.
You can also start some cabbage, cauliflower and other brassicas now for fall crops.. I'll plant my broccoli out in the garden in about 4 to 5 weeks, and the harvest will start around mid-Sept.. a great fall treat!