My strongest rec is Solbar at the Solage hotel. It's a Michelin one star in a relaxed, agri-chic
space perfect for the Napa Valley. They have private rooms. Food balances lush, delicious items (pork, lamb) with a whole list of lower calorie but nonetheless attractive options. One of the top restaurant visits, IMHO, in the Napa Valley without formality or pretense.