Melt butter in pan, add chicken, cook until well browned on both sides, remove from pan. Add onions and garlic to the same pan, cook, stirring until soft.
Blend cornflour and apricot nectar, add to pan, stir until sauce boils. Reduce heat, season with salt and pepper, add dried apricots. Return chicken to pan, cover, simmer until chicken is tender, stirring occasionally.
Add the capsicum and cook for 5 minutes, turn heat down, stir in sour cream.