I first had this at my aunt and uncle's house last summer. I'm not sure where they got it from, but it is the most amazing recipie. I've never been a big fan of tarragon, but this chicken is incredibly moist and delicious. I wasn't even that hungry and I finished off my entire plate. The key is to use fresh tarragon. This is a great light dish and can easily be doubled. Also, a little big of regular onion can be subsituted if you don't have shallots. I recommend serving this with roasted red-skinned potatoes and fresh green beans.