This lentil burger recipe is the tastiest veggie burger you'll find. It's fully vegan, and uses carrots and spices to lighten up the lentils. This recipe is easy to make and will work with just about any variation on the spices you prefer. Lentils are one of the fastest-cooking legumes, making them very handy to make quick meals. They are high in fiber, iron and folic acid, and low in fat. They are an excellent protein source for a healthy diet, whether you are a vegetarian or not.