Rinse 1 cup of lentils and drain them.
In a medium saucepan, combine the lentils with 2 cups of water or vegetable broth.
Bring to a boil, then reduce the heat to a simmer.
Cook for 20-25 minutes or until the lentils are tender.
Drain and let cool.
In a large bowl, combine the cooked lentils, chopped vegetables, and parsley or cilantro.
In a small bowl, whisk together the vinaigrette ingredients.
Pour the vinaigrette over the salad and toss to combine.
Top with feta cheese (if using) and serve.
