Bonn has many good and affordable lunch options. We have put together a short list of places just a few steps from the conference location where you can have a quick meal.
Dehly & deSander (soup & salad)
May May (Vietnamese)
Ichiban Noodle Bar (Ramen)
Iss Dich Glücklich (Persian)
Dean&David (salad and curries)
Buddha Haus (Nepalese)
If the weather is good, you can also just wander around the main market square. You will find Wurst, fish soup, fresh juices, curries, and even churros!