A regional peasant dish becomes costly once its ingredients aren’t already on hand

Evidence

you understand how the cassoulet came into being; it was evolved to make the best use of the local materials; when you have to go out and buy these things the cost is high (this is just as much the case in France as in England) and although quite a good dish can be made at moderate cost it should be remembered that tinned beans and sausages served in an earthenware casserole do not, alas, constitute a cassoulet. — David, Elizabeth, Book of Mediterranean Food, 404

Categorization

• corroborated: 2 independent passages support this claim — David, Elizabeth, Book of Mediterranean Food, 404