I ate many different lentil dishes in India and in Indian restaurants, but I don't remember ever eating anything like what we had last night. At the same time, it seems familiar. It's probably because most Indian lentil dishes are pretty much the same - with the spices taking over the whole scene. We found this recipe here, but I'm not sure we used the same black lentils. The ones we used are Urud lentils, which are very similar to mung beans. We soaked them for more than 24 hours, and then cooked them for another 3 hours, and they were still not mushy. All in all, it wasn't bad. And the naan we had with it was delicious!
From what I remember, naan should not be so puffy, but it tasted really good, so who cares?