Source is situated within one of the Hutongs (胡同) in the capital. It consists of a delightful quadrangle of buildings. When the weather is agreeable (just has when we arrived), you could sit in the courtyard and enjoy the cool evening air. There is no menu - instead you order food based on the number of people at the dinner table or the collective appetite. The food is actually inventive without too trying - we had a nice melon soup (could be cooler), minced meat with beans, etc. - all of which was lightly cooked (not drenched in oil) and beautifully presented.
What was enjoyable? The ambiance, the food and the experience of (almost) being in someone's home.
What was not enjoyable? The staff could speak better English and clearer Putonghua, as well as being more knowledgeable about what they were serving.