I love lentils! They are great and a high source of protein some where near the 17 grams per serving range. They are very tasty if done right , we used a great recipe from whole foods. Which carries a lot of great beans that are high in protein like quinoa, black beans, and pinto beans. You will not find a better selection anywhere else!
You will want to soak your beans at least 8 hours before you cook them. This will let them sprout and become a great source of vitamins and minerals. Unlocking their life giving potential will also make it easier for you to digest. Keep this in mind when you do anything grain related.