Put the buckwheat and chicken stock cube in a pan, then add two cups of water and bring to the boil. Cook for about 15 minutes, until the grains have soaked up all water. Cover with a lid and rest for 10 minutes.
Meanwhile, shred the chicken meat into a large mixing bowl.
Peel and chop the onion and garlic. Cut the red pepper into s small cubes.
Het the oil in a frying pan and sauté the onion and pepper pieces for 5 minutes, then add the garlic.
After a minute or so add the kale, lentils and the lemon juice. Season to taste. Put a lid on and cook for 5 minutes over low heat.
When the kale has wilted, add the chicken pieces to warm through. Stir in the mustard and cider vinegar.
By now the buckwheat must be ready and rested.
Put the buckwheat into the bowl and add the chicken mixture.
Toss well, then scatter the parsley leaves on top and serve.