This is an annual event in the tiny Village St. Paul in the Marais, 4ème, Métro St. Paul or Sully-Morland. Producers of foods from various regions of southwest France offer their products to taste and buy. I've eaten things from fresh oysters to woodfire roasted mushrooms. The département de Corrège is featured this year.
It's especially worth a visit if you've never seen the Village St. Paul. This is a delightful series of connected courtyards behind the rue St. Paul, between the quai des Celestins and rue St. Antoine.
It opens on Friday at 14h00 and Sat/Sun at 09h00. Feel free to drop me an email if you're coming and would like company. I am a few minutes away, just around the corner. I use Gmail. My address name is RandyParis4. (Please don't post meetups on this board.)
Website for this Marché des Producteurs de Pays (in French):