To cook a whole 500g pack of dried weight lentils (6 ½ cups) add two bay leaves and a halved onion in a pan. To cook, cover the lentils generously with water & simmer for around 30-45 minutes. How long they take depends on their type and how old they are. Be careful not to let the water run dry. The lentils are cooked when they are squishy and tender.