Wash and rinse the lentils. Put in a small saucepan and pour water over them. Bring to a boil then lower to simmer, cooking until tender, about 20-25 minutes. Drain the lentils and return them to the pot. Set aside to cool completely.

In a small bowl, whisk together juice, vinegar, and dijon mustard. Whisking constantly, slowly pour in oil, until dressing is thickened. Stir in mint and season with salt and pepper.

In a large bowl, add the lentils and the rest of the ingredients. Dress the salad (start with ¼ cup and add more if desired). Toss to coat. Refrigerate for at least 1 hour before serving.