Easier than just telling you the name of the street, I can just point you in the right direction. You go to the front of the cathedral, climb the stairs through the small park, walk a few meters to the right, and you can't miss it. It's a modern restaurant with lots of local people. The beer is great, but it's hard to find beer that's not good here, and it has hearty, traditional food. They serve a delicious and very cheap homemade soup with fried bread, smoked ham and sausage with homemade noodles. The portions are large and cheap, and you can also see the pinnacles of the cathedral.