Mistral is one of the best restaurants in the valley. They offer a solid bistro menu with all the standards (escargot, steak au poivre, dijon chicken, etc.), plus a lot of excellent seasonal specials. The staff is attentive and knowledgeable, and particularly helpful if you want help with the extensive wine list. I've been eating there for years, and never had a bad meal.
On weekdays, its usually quiet and romantic, a great place for a date. On weekends, it gets pretty noisy, a great place for dinner with friends.