Meanwhile, in a high-powered blender, add the walnuts, cumin, coriander, chili powder, paprika, chipotle powder and sea salt. Blend on low speed for a few seconds, until the walnuts are broken into pieces. You can blend more if you want it to be more powder-like, or less to still have a bit of a crunch. Transfer to a medium bowl. Add cooked lentils to the same bowl when ready and stir. Taste and add more spices if desired.