A la belle cocotte is a very nice small restaurant in the center of Nantes. I would call it rustic. Most of their dishes are served in a cocotte (iron pot).
The soup was out of this world. Our picks were a mushroom soup, then we tried a slow cooked beef stew with prunes & gnocchi, and a veal stew with mushrooms, orange zest, cheese and polenta. For dessert, we had the chocolate cream with pralines and other yummy stuff, the mango cheesecake with passion seeds and the lemon cake with berries. it was all super tasty.
The service was a bit slow, we had to keep asking for more water but only one person was serving that night, so it could be why. She was however very nice.