Toss the lamb in the gluten free flour with a little salt and plenty of freshly ground black pepper. Heat the oil in a heavy-based pan, add the lamb and stir well until tinged brown.
Stir in the stock, 2 tablespoons of the chives, dill and the bay leaf. Bring to the boil, then simmer for 30 mins.
Add the potatoes and lemon juice and cook for a further 30 mins until the potatoes are tender. Serve in soup plates or individual dishes with a spoonful of lactose free cream and a scattering of lemon zest and dill on each serving.