These are the lentils I'm currently using.
I usually cook all legumes in IP for 30 minutes now. Every once in a while I do find the beans didn't cook as thoroughly as I like so I just put the lid back on the IP and do another 30 minutes. IMHO, it is very hard to overcook beans because we prefer them well cooked. My current favorite legumes are lentils, pinto beans, and garbanzo beans.
I am currently cycling through several grains/carbs. I usually have potatoes, sweet potatoes, oatmeal, barley, quinoa, brown rice, beets, butternut squash, legumes and amaranth cooked, weighed and available to choose from. I eat 4 oz of these carb/grains 3 times a day and I try not to eat the same thing twice in a day to make sure I get a variety of nutrients. If I choose to eat legumes as my protein serving then it is a 6 oz serving instead of 4 oz.