I hesitate to share this cheap nosh with the world, because the place is so tiny and so cheap and so good. But that's also why I have to share it. Gyoza Bar in the 9e arrondissement seats about ten people and whips up the freshest, most savory and non-greasy gyoza dumplings I've ever had. Besides beer and sprout salad, it's the only thing on the menu, so it's pretty much guaranteed that the three chefs in front of you have this down. At 6€ for 8, it's the best deal around for a warm-up snack on a rainy day or a holdover bite before a night out.
For a more in-depth (fawning) review of Gyoza Bar, check out my article over at Girls' Guide to Paris.
Métro: M8, M9 to Richelieu-Druot or Grands Boulevards