Heat some olive oil in a large deep frying pan and add the leeks. Fry for 3-4 minutes then add the garlic, half the bacon lardons, and the peearl barley. Gently fry for a further 2-3 minutes, then slowly start to add the chicken stock.
As the pearl barley absorbs the stock, keep slowly adding more. When three quarters of the stock has been added (this will take 15-20 mintutes) pour in the remaining stock and gently simmer until the barley is cooked (another 10-15 minutes).
Meanwhile, in a small frying pan, heat a little oil and fry the remaining lardons until they are crisp. Set aside.
Stir the kale into the barley in batches and simmer for about 5 minutes.
Season to taste, stir in the creme fraiche and lemon juice, then serve sprinkled with parsley if desired. Sprinkle the crispy lardons on top.