Cocoa powder in hot milk was his favorite drink. The reason for that, as he put it, was that when he was about to leave for Europe for the first time, he visited Hazrat Khalifatul-Masih I (ra) for his prayers and general guidance.
One of his advice was about the use of cocoa. He said: “You are going to England which is a cold country. People think that they need to drink alcohol to protect themselves from the cold. I am a physician and know very well that it is incorrect. If you feel like protecting yourself from cold, use cocoa. It is nourishing and protects from the ill effects of cold.” He remembered that advice always and benefited from it a great deal.