Put the lentils into a large bowl of water, thoroughly wash them with your hands then leave in fresh water for 10 minutes. Repeat this process twice more, so they have about ½ hour in total soaking.
Meanwhile, peel & finely chop the onions & garlic. Chop the rosemary leaves.
Clean and peel (if not organic) the sweet potato & carrot then chop into smallish bits.
When the lentils are properly soaked, heat up the pressure cooker pan and add the oil. Gently fry the onion and garlic, then after a couple of minutes stir in the chopped sweet potato & carrot. Stir in the rosemary leaves.
Strain the lentils and add to the pot, followed by the stock and seasoning. Stir well, bring to the boil and pressure cook for 10-12 minutes. Allow to cool by itself.
Meanwhile you will have washed and roughly chopped the kale which can now be added to the pan and cooked (covered but not under pressure) for 7 or 8 minutes, stirring occasionally.
Serve sprinkled with fresh herbs of your choice, a dash of apple cider vinegar and chunks of crusty fresh bread.