In a deep, 2 litre , heat-resistant, non-metallic casserole, Placevegetable oil, onion and tomatoes and heat, uncovered, in Microwave Oven 4minutes or until tender. Set aside.
In a small, heat-resistant, non-metallic bowl melt butter in MicrowaveOven 30 seconds.
Blend in flour, salt, pepper and chicken stock.
Heat, uncovered, in Microwave Oven 3 minutes or untiI thickened andsmooth. Stir occasionally. Add sauce and cooked lamb to onion-tomato mixture. Stir to combine.
Heat, covered, in Microwave Oven 5 to 7 minutes or until almost heatedthrough (time will depend on temperature of cooked lamb). Top with mashedpotatoes and heat, uncovered, an additional 3 to 5 minutes or until servingtemperature is reached. Variation: Cooked beef chunks, ground beef or ground lamb may besubstitutedfor cooked lamb.