Toast the walnuts in a skillet over medium heat for 3-5 minutes, until they become slightly browned. Remove from the skillet and roughly chop.

Cook the onions in the skillet on medium heat, using ¼ cup of vegetable broth as the cooking liquid. Stir occasionally and allow the onions to soften.

Meanwhile, steam the green beans. Fill a large saucepan with water place a steamer basket over top. Bring the water to a boil. Add the green beans and steam until just tender, around 3-5 minutes.

Transfer the beans to the skillet with the onions and cook over medium heat for 2 minutes, adding additional vegetable broth if the beans start to stick.

To serve, toss the walnuts with the beans and season with salt and pepper.