Place the flour and paprika in a small plastic bag and season well. Add the chicken pieces to the bag and shake to coat.
Spray a large frying pan with a fine coating of spray oil or heat the butter, and gently fry the chicken until golden. Transfer to a bowl with a slotted spoon and cover to keep warm. Heat 300 ml of the stock in the pan, add the onions and garlic and simmer for 10 minutes. Add the mushrooms, sherry, and chicken to the pan along with the remaining stock and a little seasoning to taste. Cook for 5 minutes, stirring until all the ingredients are heated through and the sauce has thickened up. Remove from the heat and stir in the cream. Sprinkle with chives and serve with noodles or rice.