Heat oil in a large frying pan over medium-high heat. Add chicken. Cook, stirring, for 5 minutes or until browned. Transfer to a bowl.

Add onion, garlic and mushroom to the pan and cook, stirring, for 5 minutes or until onion is softened and mushroom is browned. Add paprika. Cook, stirring, for 1 minute. Add tomato paste, Worcestershire sauce and stock. Bring to the boil. Return chicken to pan. Simmer for 5 to 7 minutes or until chicken is cooked through.
Stir in sour cream and spinach. Cook for 1 to 2 minutes or until heated through. Serve with steamed rice and scatter chives on the top.