Rinse lentils thoroughly and drain.

In a medium saucepan, combine lentils, water, and bay leaf. Bring to a boil, then lower the heat and simmer for 20-25 minutes or until lentils are tender but not mushy. Drain and discard bay leaf.

While lentils are cooking, heat olive oil in a large skillet over medium heat. Add onion, carrot, and celery. Sauté until vegetables are soft, about 5-6 minutes.

Add cooked lentils to the skillet with vegetables. Stir in cranberries, walnuts, and parsley.

In a small bowl, whisk together balsamic vinegar, maple syrup, salt, and pepper.

Pour the dressing over the lentil mixture and toss well to combine.

Serve warm or at room temperature.