I think a piece of salmon or a baked chicken thigh would be great matches for this dish, or it could be a meal on its own. Enjoy it warm or room temperature. Brown or green lentils would work in place of the French lentils, but I wouldn’t use red ones.
It’s the mixture of Dijon, red wine vinegar, onion and maple syrup that takes this dish over the top. Use it on other combos of beans and vegetables – cannellini beans and arugula with halved cherry tomatoes, for instance.