There were several grocery-stores that had some gluten-free food, like Biocoop and Monop (the same as I found in Paris), but the very best was “Parapharmacie Lafayette”, 10 boulevard de Strasbourg, close to the metro station Jean Jaures.
They had the usual brands as we have at home, but also lots of other brands I have never seen before. There were several shelves and I think, for a little while at least, I was in gluten-free heaven! However I didn’t buy much as I didn’t need anything, but I bought some boxes with “Le Pain des Fleurs” crackers. We have them at home, but they are so expencive I don’t bother to buy them. Here it was half the price so I am planning on stocking up some more to fill my suitcase!
I also bought some seasonings as I found “massala-mix” without onion and garlic in another shop, unfortunately I don’t remember the name of the store, but it was the grocery-store next to the Parapharmacie Lafayette, something with “International….”.
If you are stuck there are lots of sushi-restaurants and even two Mc. Donalds, but I take it that most restaurants have “beef and French fries” if you ask.