Crêperies are the default eating option in Brittany, and Vannes has several good ones in the old town. The Crêperie des Remparts, near the rampart walls, is a solid choice for a proper Breton lunch: buckwheat galettes with ham, egg, and cheese (the complète), or more elaborate fillings with andouille sausage or smoked salmon, followed by a sweet crêpe with caramel au beurre salé. A glass of dry cider from the earthenware bolée is the correct accompaniment.
The formula de galette-crêpe-cidre is one of the best-value lunches in France — filling, local, and cheap. Most crêperies in Vannes are open for lunch and dinner except Monday.