Saute onion, celery, and green pepper in margarine; add flour and curry powder and cook thoroughly. Add milk; cook, stirring constantly, until thick and smooth. Add sherry, chicken, and mushrooms; simmer for 30 minutes. Add lemon juice to mixture 5 minutes before serving.

Serve chicken curry over cooked rice. Top with your choice of condiments; diced crisp bacon, diced hard-cooked eggs, slivered almonds, flaked coconut, fried onions, salted peanuts, seedless white raisins, and finely chopped sweet pickles.