As a complement to the Rue Montorgueil and rue du Nil food stores (read here, and there), every Sunday morning there is an open food market right around the corner, literally 3mn walk away.
Fishmonger, cheesemonger, florist, produce … name it, if it is fresh food related, you will find it. The atmosphere is that of a village, and you can enjoy a sunny morning coffee on the terrasse of the Florida along the way.
In this respect, the best organic produce store is at the South end of the market, right in front of the Florida coffee.
Rue Jean Jacques Rousseau 