Kosher salt and freshly ground black pepper(to taste)
Bring a large pot of generously salted water to a boil. Drop the beans into the water and let them cook for 3 minutes until they start to become tender. Drain the beans in a colander and run cold water over them to stop the cooking and preserve the color.
Peel the clementines and cut each segment in half crosswise. Cut the cooled beans in half cross wise.
In a small bowl or container, combine the olive oil, vinegar, shallots, mustard, thyme, salt, and pepper. Whisk or shake to combine.
Place the beans and orange segments in a large bowl and drizzle over the dressing. Toss to combine thoroughly. Add the feta and toss again gently to combine. Serve at room temperature or chilled.
Be careful not to cook the green beans for more than 4 minutes, depending on thickness, as they will lose their vibrant green color and become limp. You want crisp-tender green beans.
You can leave the green beans long, or halve them to make them more bite-sized.
This makes a great salad to keep in the fridge and serve the next day. Because the beans are more hearty than lettuce, they won't wilt or lose color in the fridge. They can be cooked and tossed with the dressing up to 2 days ahead of time. Add the clementines and the feta just before serving.