Whole class roleplay - food shopping

Divide the class into shopkeepers & customers. Shopkeepers can make signs to show which shop they have, while customers find out how to say the food on their lists in French. Set up the classroom so tables are "shops" and the customers go around to buy the food on their lists. They have to write down the price of each thing. I get my pupils to police each other for anyone speaking English, and the shopkeepers can give a stamp to anyone who they think has done really well at asking for the food in French.