Mussels and Frites in SS or CC
About five years ago The Commons in Provincetown, toward the east end, had moule et frite on the lunch blackboard menu, and it was consistently excellent. The next year they did not offer it during my time there.
Having not been to Provincetown the past three summers, not sure if they are even still in business. It was a favorite lunch spot, excellent value in sandwiches, pizzas, salads, fish & chips, etc., but they never seemed to be too busy. Upper deck dining on a summer afternoon was a favorite experience.