Place the lentils in a large saucepan. Cover with the stock and boil for 10 minutes. Lower the heat and cover, simmering gently, for 10-15 minutes until tender.
Meanwhile, heat the oil over a medium heat in a large sauté pan. Add the onions and celery, lower the heat, and cook for 10 minutes until the onions have softened and just start to colour. Add the minced garlic and mushrooms and sauté for another 3 minutes. Add the cumin, diced red chilli and a few fresh gratings of nutmeg and cook for an additional 2-3 minutes. Add half the kale and, as it starts to shrink down, add the rest of the kale and cook for 8-10 minutes until wilted.
Drain the lentils, add them to the kale mixture and stir through, seasoning lightly. Pat down the mixture and create 4 wells evenly spaced apart. Carefully crack an egg into each well. Cover the pan, then cook on low for 8-10 minutes, until the whites are set and the yolks are nice and runny.
Once the eggs are cooked, remove from the heat and sprinkle over the feta, parsley and thinly sliced red chilli with some freshly cracked black pepper. Serve with lots of lovely crusty bread.