Prepare a pot of salted water for boiling soba.
Preheat a large pan over medium high heat. First sautee the broccoli with a bit of cooking spray and a pinch of salt for about 5 minutes. Cover the pan and flip once or twice. Broccoli should be browned in some spots. Add a splash of water at the end, cover for another minute. The pan should be steaming. Remove brocolli from pan and set aside. (By the way, that is my favorite way to prepare broccoli in general if I am serving it on the side.)
At this point, the water should be boiling. Use a mug to remove 1/2 a cup of water, you can use that to mix into your miso in a few steps. Then cook the noodles according to package directions, usually boiling for under 5 minutes. Drain when ready.
Now we’ll put everything together. Preheat the large pan again, over medium heat. Saute the garlic in oil for about a minute, until fragrant. Add chard, green onion and salt and saute for about 5 minutes, until wilted. Add beans to heat through.
In the meantime, in a mug or measuring cup, mix together miso and warm water until relatively smooth.
Add drained noodles to the pan, along with the miso and broccoli. Saute for about 2 minutes, using a pasta spoon, making sure everything is nice and coated. Taste for salt. To serve, top with sesame seeds and green onions and keep the Sriracha close at hand.