I usually do soak the lentils overnight. Just put them in a basin and cover with cold water. I rinse them several times the next day and drain through a sieve. I either use all lentils or a mixture of lentils and the soup / broth mix that has pearl barley and peas etc. My stew consisted of the broth mix, chopped onion, chopped leeks, chopped carrot and diced potatoes. We had gammon cooked in the pressure cooker on Sunday and I saved the stock to use for the soup. You can use just plain water or a stock cube. Put all ingredients into a saucepan/ pressure cooker or slow cooker and add seasoning to your taste. I would have used a swede as well but they didn't have any in the shop.