Put diced chicken and peas in casserole. In saucepan saute onion in 1 tlbs margarine. Mix mushroom soup and milk and marjoram to-gether in bowl and then add to onion in pan, heat well and pour over chicken & peas in casserole. Make biscuit and put on top or use bisquik mix. Bake in hot oven 230ºC or 20 min.