You can buy a prepared sandwich at noon here - it's organic slowly made sourdough baguette with grilled vegetables and sun-dried tomatoes. It does contain parmezan cheese so it's not vegan-friendly. There's a meat option available.
The best thing is you can watch the baker work and pull out a bunch of baguettes while you chew on yours. Amazing taste, the breads are also very hearty, especially the heavy siegle one.
Cons: not too cheap €3.5 for a small baguette, not a lot of room for groups to dine!