St Arnold on tiny Jefferson St has a full page of mussels and is often considered a mussel bar, though I chose differently for brunch. Shared an onion soup with melted brie and then got a waterzooi over a Liege waffle.
The onion soup has a nice creamy flavor (the color is very light), and is a good order.
Unfortunately the waffle comes in a bowl drowned in the waterzooi, which is a buttery and soupy chicken and vegetables mixture. So you don't get the crispiness of the waffle. Also, I guess they only have one waffle batter, because it was sweet like you would get with a dessert waffle. I missed the old Locolat in Adams Morgan that would offer savory waffles like garlic or pesto topped with their stews and grilled vegetables. This was nowhere close to that quality.