Lau — pronounced something like ‘low’ — is perhaps one of the most popular dishes in Hanoi, particularly in the cooler months. It’s a similar set up to that seen in other countries in the region :a pan of simmering stock is put on a gas stove on the table and diners cook their own beef, chicken, fish, noodles, veggies and so on. It’s a very social meal, fitting perfectly with Vietnamese eating culture.
It’s widely available around town, including at bia hoi joints; the place on Hang Tre I mentioned in my bia hoi post was doing a roaring trade on my last visit but there are a couple of places where it’s dominant — “lau streets”, if you will.
Nearest to Old Quarter is Phung Hung, on the western edge of Old Quarter, where at least half a dozen places vie for attention. It’s also near to Food Street, which has a few lau options also.
Slightly further afield, but definitely worth the trek — is Truc Bach. Running along the northeastern edge of Truc Bach lake, Truc Bach street is lined with lau restaurants, all with tables and mats set out along the lakeside. Plenty of places, many with higher seating, are located along the parallel street, Pho Duc Chinh.
As for price, sometimes you can order a certain sized portion and share it between however many people you are, other times they will bring enough for everyone and price it accordingly. It’s difficult to give an estimate as it depends on location, ingredients, how hungry you are, and so on, but budget for around maybe 150,000 VND per person. Make sure you check the price first, particularly in the touristy parts of town.