Puy lentils are a dark green and larger than brown lentils. Brown ones will cook in about half an hour, maybe a little less. Why not cook them separately and add later with any remaining liquid once the soup is made? I'm a great lentil fan. I don't eat brown lentils that much, mainly the green lentils called Salamanca lentils here in Spain and Puy lentils. I ought to eat brown ones more, they have such a satisfying, homely flavour. In my poorer days, I'd fry up some diced bacon and onion and then add some pre-cooked or canned brown lentils and feel like I'd dined like a lord (well, like a lady in my case). If you like to add a lot of salt to your soup while it's cooking, GB, you might do better to follow my suggestion and cook the lentils separately. Lentils seem to cook slower in the presence of salt, for some reason that I don't understand.
